diff --git a/DEPS b/DEPS
index 6a842ff1a6867..e7a5c4e9596d7 100644
--- a/DEPS
+++ b/DEPS
@@ -51,7 +51,7 @@ vars = {
 
   # co19 is a cipd package. Use update.sh in tests/co19[_2] to update these
   # hashes.
-  "co19_rev": "2a9309cd36effe3b083df6a2761fea6b7213c670",
+  "co19_rev": "c38e027467efb69c754b198fe0d4029c38cfe72b",
   # This line prevents conflicts when both packages are rolled simultaneously.
   "co19_2_rev": "cdab7e4e26f3dd534bcb297ff3f9e9aa5c7a04fb",
 
diff --git a/pkg/_fe_analyzer_shared/lib/src/parser/value_kind.dart b/pkg/_fe_analyzer_shared/lib/src/parser/value_kind.dart
index 9b05436fb76cd..d9aaa699006c7 100644
--- a/pkg/_fe_analyzer_shared/lib/src/parser/value_kind.dart
+++ b/pkg/_fe_analyzer_shared/lib/src/parser/value_kind.dart
@@ -71,10 +71,20 @@ class UnionValueKind implements ValueKind {
 
 /// Helper method for creating a list of [ValueKind]s of the given length
 /// [count].
-List<ValueKind> repeatedKinds(ValueKind kind, int count) {
+List<ValueKind> repeatedKind(ValueKind kind, int count) {
   return new List.generate(count, (_) => kind);
 }
 
+/// Helper method for creating a list of [count] repetitions of a sequence of
+/// [ValueKind]s.
+List<ValueKind> repeatedKinds(List<ValueKind> kinds, int count) {
+  List<ValueKind> list = [];
+  for (int i = 0; i < count; i++) {
+    list.addAll(kinds);
+  }
+  return list;
+}
+
 /// Helper method for creating a union of a list of [ValueKind]s.
 ValueKind unionOfKinds(List<ValueKind> kinds) {
   return new UnionValueKind(kinds);
diff --git a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
index a3764b3722f5c..65979cb30c8e0 100644
--- a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
@@ -884,7 +884,7 @@ class BodyBuilder extends StackListenerImpl
 
   @override
   void endMetadataStar(int count) {
-    assert(checkState(null, repeatedKinds(ValueKinds.Expression, count)));
+    assert(checkState(null, repeatedKind(ValueKinds.Expression, count)));
     debugEvent("MetadataStar");
     if (count == 0) {
       push(NullValue.Metadata);
@@ -2275,7 +2275,7 @@ class BodyBuilder extends StackListenerImpl
           libraryFeatures.patterns, case_.charOffset, case_.charCount);
       Pattern pattern = toPattern(pop());
       Expression expression = popForValue();
-      push(new Condition(expression, pattern, guard));
+      push(new Condition(expression, new PatternGuard(pattern, guard)));
     } else {
       assert(checkState(token, [
         unionOfKinds([
@@ -2517,20 +2517,19 @@ class BodyBuilder extends StackListenerImpl
     ]));
     debugEvent("endCaseExpression");
     Object? value = pop();
+    constantContext = pop() as ConstantContext;
     if (value is Pattern) {
-      constantContext = pop() as ConstantContext;
-      // TODO(paulberry): handle guard
-      super.push(toPattern(value));
+      super.push(new PatternGuard(value, guard));
+    } else if (guard != null) {
+      super.push(new PatternGuard(toPattern(value), guard));
     } else {
       Expression expression = toValue(value);
-      constantContext = pop() as ConstantContext;
-      // TODO(paulberry): handle guard
       super.push(expression);
     }
     assert(checkState(colon, [
       unionOfKinds([
         ValueKinds.Expression,
-        ValueKinds.Pattern,
+        ValueKinds.PatternGuard,
       ])
     ]));
   }
@@ -3434,9 +3433,10 @@ class BodyBuilder extends StackListenerImpl
     typeInferrer.assignedVariables.beginNode();
     Condition condition = peek() as Condition;
     enterLocalScope("then");
-    Pattern? pattern = condition.pattern;
-    if (pattern != null) {
-      for (VariableDeclaration variable in pattern.declaredVariables) {
+    PatternGuard? patternGuard = condition.patternGuard;
+    if (patternGuard != null) {
+      for (VariableDeclaration variable
+          in patternGuard.pattern.declaredVariables) {
         declareVariable(variable, scope);
         typeInferrer.assignedVariables.declare(variable);
       }
@@ -3468,13 +3468,12 @@ class BodyBuilder extends StackListenerImpl
         pop() as AssignedVariablesNodeInfo;
     Statement thenPart = popStatement();
     Condition condition = pop() as Condition;
-    Pattern? pattern = condition.pattern;
-    Expression? guard = condition.guard;
+    PatternGuard? patternGuard = condition.patternGuard;
     Expression expression = condition.expression;
     Statement node;
-    if (pattern != null) {
+    if (patternGuard != null) {
       node = new IfCaseStatement(
-          expression, pattern, guard, thenPart, elsePart, ifToken.charOffset);
+          expression, patternGuard, thenPart, elsePart, ifToken.charOffset);
     } else {
       node = forest.createIfStatement(
           offsetForToken(ifToken), expression, thenPart, elsePart);
@@ -3962,7 +3961,7 @@ class BodyBuilder extends StackListenerImpl
     Token forKeyword = pop() as Token;
 
     assert(checkState(endToken, <ValueKind>[
-      /* expressions */ ...repeatedKinds(
+      /* expressions */ ...repeatedKind(
           unionOfKinds(
               <ValueKind>[ValueKinds.Expression, ValueKinds.Generator]),
           updateExpressionCount),
@@ -4067,7 +4066,7 @@ class BodyBuilder extends StackListenerImpl
       int count, Token leftBracket, Token? constKeyword, Token rightBracket) {
     debugEvent("LiteralList");
     assert(checkState(leftBracket, [
-      ...repeatedKinds(
+      ...repeatedKind(
           unionOfKinds([
             ValueKinds.Generator,
             ValueKinds.Expression,
@@ -4120,7 +4119,7 @@ class BodyBuilder extends StackListenerImpl
   void handleListPattern(int count, Token leftBracket, Token rightBracket) {
     debugEvent("ListPattern");
     assert(checkState(leftBracket, [
-      ...repeatedKinds(
+      ...repeatedKind(
           unionOfKinds([
             ValueKinds.Generator,
             ValueKinds.Expression,
@@ -4167,7 +4166,7 @@ class BodyBuilder extends StackListenerImpl
     debugEvent("RecordLiteral");
     assert(checkState(
         token,
-        repeatedKinds(
+        repeatedKind(
             unionOfKinds([
               ValueKinds.Generator,
               ValueKinds.Expression,
@@ -4260,7 +4259,7 @@ class BodyBuilder extends StackListenerImpl
     debugEvent("RecordPattern");
     assert(checkState(
         token,
-        repeatedKinds(
+        repeatedKind(
             unionOfKinds([
               ValueKinds.Generator,
               ValueKinds.Expression,
@@ -4331,7 +4330,7 @@ class BodyBuilder extends StackListenerImpl
   ) {
     debugEvent("LiteralSetOrMap");
     assert(checkState(leftBrace, [
-      ...repeatedKinds(
+      ...repeatedKind(
           unionOfKinds([
             ValueKinds.Expression,
             ValueKinds.Generator,
@@ -4429,7 +4428,7 @@ class BodyBuilder extends StackListenerImpl
   void handleMapPattern(int count, Token leftBrace, Token rightBrace) {
     debugEvent('MapPattern');
     assert(checkState(leftBrace, [
-      ...repeatedKinds(ValueKinds.MapPatternEntry, count),
+      ...repeatedKind(ValueKinds.MapPatternEntry, count),
       ValueKinds.TypeArgumentsOrNull,
     ]));
 
@@ -4678,7 +4677,7 @@ class BodyBuilder extends StackListenerImpl
     debugEvent("RecordType");
     assert(checkState(leftBracket, [
       if (hasNamedFields) ValueKinds.RecordTypeFieldBuilderListOrNull,
-      ...repeatedKinds(ValueKinds.RecordTypeFieldBuilder,
+      ...repeatedKind(ValueKinds.RecordTypeFieldBuilder,
           hasNamedFields ? count - 1 : count),
     ]));
 
@@ -4746,7 +4745,7 @@ class BodyBuilder extends StackListenerImpl
   void endRecordTypeNamedFields(int count, Token leftBracket) {
     debugEvent("RecordTypeNamedFields");
     assert(checkState(leftBracket, [
-      ...repeatedKinds(ValueKinds.RecordTypeFieldBuilder, count),
+      ...repeatedKind(ValueKinds.RecordTypeFieldBuilder, count),
     ]));
     List<RecordTypeFieldBuilder>? fields =
         const FixedNullableList<RecordTypeFieldBuilder>()
@@ -6271,8 +6270,8 @@ class BodyBuilder extends StackListenerImpl
 
     Object? entry = pop();
     Condition condition = pop() as Condition;
-    assert(condition.pattern == null,
-        "Unexpected pattern in control flow if: ${condition.pattern}.");
+    assert(condition.patternGuard == null,
+        "Unexpected pattern in control flow if: ${condition.patternGuard}.");
     Token ifToken = pop() as Token;
 
     TreeNode node;
@@ -6315,8 +6314,8 @@ class BodyBuilder extends StackListenerImpl
     AssignedVariablesNodeInfo assignedVariablesInfo =
         pop() as AssignedVariablesNodeInfo;
     Condition condition = pop() as Condition; // parenthesized expression
-    assert(condition.pattern == null,
-        "Unexpected pattern in control flow if: ${condition.pattern}.");
+    assert(condition.patternGuard == null,
+        "Unexpected pattern in control flow if: ${condition.patternGuard}.");
     Token ifToken = pop() as Token;
 
     TreeNode node;
@@ -6721,8 +6720,8 @@ class BodyBuilder extends StackListenerImpl
       /* break target = */ ValueKinds.BreakTarget,
     ]));
     Condition condition = pop() as Condition;
-    assert(condition.pattern == null,
-        "Unexpected pattern in do statement: ${condition.pattern}.");
+    assert(condition.patternGuard == null,
+        "Unexpected pattern in do statement: ${condition.patternGuard}.");
     Expression expression = condition.expression;
     Statement body = popStatement();
     JumpTarget continueTarget = exitContinueTarget()!;
@@ -7060,8 +7059,8 @@ class BodyBuilder extends StackListenerImpl
     ]));
     Statement body = popStatement();
     Condition condition = pop() as Condition;
-    assert(condition.pattern == null,
-        "Unexpected pattern in while statement: ${condition.pattern}.");
+    assert(condition.patternGuard == null,
+        "Unexpected pattern in while statement: ${condition.patternGuard}.");
     Expression expression = condition.expression;
     JumpTarget continueTarget = exitContinueTarget()!;
     JumpTarget breakTarget = exitBreakTarget()!;
@@ -7192,24 +7191,36 @@ class BodyBuilder extends StackListenerImpl
   void beginSwitchCase(int labelCount, int expressionCount, Token firstToken) {
     debugEvent("beginSwitchCase");
     int count = labelCount + expressionCount;
+    assert(checkState(
+        firstToken,
+        repeatedKind(
+            unionOfKinds([
+              ValueKinds.Label,
+              ValueKinds.Expression,
+              ValueKinds.PatternGuard,
+            ]),
+            count)));
     List<Object>? labelsExpressionsAndPatterns =
         const FixedNullableList<Object>()
             .popNonNullable(stack, count, dummyLabel);
     List<Label>? labels =
         labelCount == 0 ? null : new List<Label>.filled(labelCount, dummyLabel);
-    List<Expression> expressions = new List<Expression>.filled(
+    bool containsPatterns = false;
+    List<Object> expressionOrPatterns = new List<Object>.filled(
         expressionCount, dummyExpression,
         growable: true);
     int labelIndex = 0;
-    int expressionIndex = 0;
+    int expressionOrPatternIndex = 0;
     if (labelsExpressionsAndPatterns != null) {
       for (Object labelExpressionOrPattern in labelsExpressionsAndPatterns) {
         if (labelExpressionOrPattern is Label) {
           labels![labelIndex++] = labelExpressionOrPattern;
-        } else if (labelExpressionOrPattern is Pattern) {
-          // TODO(johnniwinther): Handle patterns.
+        } else if (labelExpressionOrPattern is PatternGuard) {
+          expressionOrPatterns[expressionOrPatternIndex++] =
+              labelExpressionOrPattern;
+          containsPatterns = true;
         } else {
-          expressions[expressionIndex++] =
+          expressionOrPatterns[expressionOrPatternIndex++] =
               labelExpressionOrPattern as Expression;
         }
       }
@@ -7233,9 +7244,16 @@ class BodyBuilder extends StackListenerImpl
         }
       }
     }
-    push(expressions);
+    push(expressionOrPatterns);
+    push(containsPatterns);
     push(labels ?? NullValue.Labels);
     enterLocalScope("switch case");
+    assert(checkState(firstToken, [
+      ValueKinds.Scope,
+      ValueKinds.LabelListOrNull,
+      ValueKinds.Bool,
+      ValueKinds.ExpressionOrPatternGuardList,
+    ]));
   }
 
   @override
@@ -7248,22 +7266,51 @@ class BodyBuilder extends StackListenerImpl
       Token firstToken,
       Token endToken) {
     debugEvent("SwitchCase");
+    assert(checkState(firstToken, [
+      ...repeatedKind(ValueKinds.Statement, statementCount),
+      ValueKinds.Scope,
+      ValueKinds.LabelListOrNull,
+      ValueKinds.Bool,
+      ValueKinds.ExpressionOrPatternGuardList,
+    ]));
     // We always create a block here so that we later know that there's always
     // one synthetic block when we finish compiling the switch statement and
     // check this switch case to see if it falls through to the next case.
     Statement block = popBlock(statementCount, firstToken, null);
     exitLocalScope();
     List<Label>? labels = pop() as List<Label>?;
-    List<Expression> expressions = pop() as List<Expression>;
-    List<int> expressionOffsets = <int>[];
-    for (Expression expression in expressions) {
-      expressionOffsets.add(expression.fileOffset);
-    }
     assert(labels == null || labels.isNotEmpty);
-    push(new SwitchCaseImpl(expressions, expressionOffsets, block,
-        isDefault: defaultKeyword != null, hasLabel: labels != null)
-      ..fileOffset = firstToken.charOffset);
+    bool containsPatterns = pop() as bool;
+    List<Object> expressionsOrPatternGuards = pop() as List<Object>;
+    if (containsPatterns) {
+      List<PatternGuard> patternGuards = <PatternGuard>[];
+      for (Object expressionOrPatternGuard in expressionsOrPatternGuards) {
+        if (expressionOrPatternGuard is PatternGuard) {
+          patternGuards.add(expressionOrPatternGuard);
+        } else {
+          patternGuards
+              .add(new PatternGuard(toPattern(expressionOrPatternGuard)));
+        }
+      }
+      push(new PatternSwitchCase(firstToken.charOffset, patternGuards, block,
+          isDefault: defaultKeyword != null, hasLabel: labels != null));
+    } else {
+      List<Expression> expressions = <Expression>[];
+      List<int> expressionOffsets = <int>[];
+      for (Object expressionOrPatternGuard in expressionsOrPatternGuards) {
+        Expression expression = expressionOrPatternGuard as Expression;
+        expressions.add(expression);
+        expressionOffsets.add(expression.fileOffset);
+      }
+      push(new SwitchCaseImpl(expressions, expressionOffsets, block,
+          isDefault: defaultKeyword != null, hasLabel: labels != null)
+        ..fileOffset = firstToken.charOffset);
+    }
     push(labels ?? NullValue.Labels);
+    assert(checkState(firstToken, [
+      ValueKinds.LabelListOrNull,
+      ValueKinds.SwitchCase,
+    ]));
   }
 
   @override
@@ -7271,21 +7318,29 @@ class BodyBuilder extends StackListenerImpl
     debugEvent("SwitchStatement");
     assert(checkState(switchKeyword, [
       /* cases = */ ValueKinds.SwitchCaseList,
+      /* containsPatterns */ ValueKinds.Bool,
       /* break target = */ ValueKinds.BreakTarget,
       /* switch scope = */ ValueKinds.SwitchScopeOrNull,
       /* local scope = */ ValueKinds.Scope,
       /* expression = */ ValueKinds.Condition,
     ]));
     List<SwitchCase> cases = pop() as List<SwitchCase>;
+    bool containsPatterns = pop() as bool;
     JumpTarget target = exitBreakTarget()!;
     exitSwitchScope();
     exitLocalScope();
     Condition condition = pop() as Condition;
-    assert(condition.pattern == null,
-        "Unexpected pattern in switch statement: ${condition.pattern}.");
+    assert(condition.patternGuard == null,
+        "Unexpected pattern in switch statement: ${condition.patternGuard}.");
     Expression expression = condition.expression;
-    Statement switchStatement = new SwitchStatement(expression, cases)
-      ..fileOffset = switchKeyword.charOffset;
+    Statement switchStatement;
+    if (containsPatterns) {
+      switchStatement = new PatternSwitchStatement(
+          switchKeyword.charOffset, expression, cases);
+    } else {
+      switchStatement = new SwitchStatement(expression, cases)
+        ..fileOffset = switchKeyword.charOffset;
+    }
     Statement result = switchStatement;
     if (target.hasUsers) {
       LabeledStatement labeledStatement = forest.createLabeledStatement(result);
@@ -7300,6 +7355,13 @@ class BodyBuilder extends StackListenerImpl
   @override
   void endSwitchBlock(int caseCount, Token beginToken, Token endToken) {
     debugEvent("SwitchBlock");
+    assert(checkState(
+        beginToken,
+        repeatedKinds([
+          ValueKinds.LabelListOrNull,
+          ValueKinds.SwitchCase,
+        ], caseCount)));
+    bool containsPatterns = false;
     List<SwitchCase> cases =
         new List<SwitchCase>.filled(caseCount, dummySwitchCase, growable: true);
     for (int i = caseCount - 1; i >= 0; i--) {
@@ -7313,6 +7375,9 @@ class BodyBuilder extends StackListenerImpl
           }
         }
       }
+      if (current is PatternSwitchCase) {
+        containsPatterns = true;
+      }
     }
     for (int i = 0; i < caseCount - 1; i++) {
       SwitchCase current = cases[i];
@@ -7347,7 +7412,12 @@ class BodyBuilder extends StackListenerImpl
       }
     }
 
+    push(containsPatterns);
     push(cases);
+    assert(checkState(beginToken, [
+      ValueKinds.SwitchCaseList,
+      ValueKinds.Bool,
+    ]));
   }
 
   @override
@@ -8149,7 +8219,7 @@ class BodyBuilder extends StackListenerImpl
     debugEvent("ObjectPattern");
     assert(checkState(
         beginToken,
-        repeatedKinds(
+        repeatedKind(
             unionOfKinds([
               ValueKinds.Expression,
               ValueKinds.Generator,
@@ -8764,15 +8834,11 @@ class _FindChildVisitor extends Visitor<void> with VisitorVoidMixin {
 
 class Condition {
   final Expression expression;
-  final Pattern? pattern;
-  final Expression? guard;
+  final PatternGuard? patternGuard;
 
-  Condition(this.expression, [this.pattern, this.guard])
-      : assert(guard == null || pattern != null,
-            "Unexpected guard without pattern.");
+  Condition(this.expression, [this.patternGuard]);
 
   @override
   String toString() => 'Condition($expression'
-      '${pattern != null ? ',$pattern' : ''}'
-      '${guard != null ? ',$guard' : ''})';
+      '${patternGuard != null ? ',$patternGuard' : ''})';
 }
diff --git a/pkg/front_end/lib/src/fasta/kernel/internal_ast.dart b/pkg/front_end/lib/src/fasta/kernel/internal_ast.dart
index 3c9e15348eba1..3940e5eb737fb 100644
--- a/pkg/front_end/lib/src/fasta/kernel/internal_ast.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/internal_ast.dart
@@ -412,6 +412,142 @@ class SwitchCaseImpl extends SwitchCase {
   }
 }
 
+/// A [Pattern] with an optional guard [Expression].
+class PatternGuard extends TreeNode with InternalTreeNode {
+  Pattern pattern;
+  Expression? guard;
+
+  PatternGuard(this.pattern, [this.guard]) {
+    pattern.parent = this;
+    guard?.parent = this;
+  }
+
+  @override
+  void toTextInternal(AstPrinter printer) {
+    pattern.toTextInternal(printer);
+    if (guard != null) {
+      printer.write(' when ');
+      printer.writeExpression(guard!);
+    }
+  }
+
+  @override
+  String toString() => 'PatternGuard(${toStringInternal()})';
+}
+
+class PatternSwitchCase extends TreeNode
+    with InternalTreeNode
+    implements SwitchCase {
+  final List<PatternGuard> patternGuards;
+  @override
+  Statement body;
+
+  @override
+  bool isDefault;
+
+  final bool hasLabel;
+
+  PatternSwitchCase(int fileOffset, this.patternGuards, this.body,
+      {required this.isDefault, required this.hasLabel}) {
+    this.fileOffset = fileOffset;
+  }
+
+  @override
+  void toTextInternal(AstPrinter printer) {
+    for (int index = 0; index < patternGuards.length; index++) {
+      if (index > 0) {
+        printer.newLine();
+      }
+      printer.write('case ');
+      patternGuards[index].toTextInternal(printer);
+      printer.write(':');
+    }
+    if (isDefault) {
+      if (patternGuards.isNotEmpty) {
+        printer.newLine();
+      }
+      printer.write('default:');
+    }
+    printer.incIndentation();
+    Statement? block = body;
+    if (block is Block) {
+      for (Statement statement in block.statements) {
+        printer.newLine();
+        printer.writeStatement(statement);
+      }
+    } else {
+      printer.write(' ');
+      printer.writeStatement(body);
+    }
+    printer.decIndentation();
+  }
+
+  @override
+  String toString() {
+    return "PatternSwitchCase(${toStringInternal()})";
+  }
+
+  @override
+  List<Expression> get expressions =>
+      throw new UnimplementedError('PatternSwitchCase.expressions');
+
+  @override
+  List<int> get expressionOffsets =>
+      throw new UnimplementedError('PatternSwitchCase.expressionOffsets');
+}
+
+class PatternSwitchStatement extends InternalStatement {
+  Expression expression;
+  final List<SwitchCase> cases;
+
+  PatternSwitchStatement(int fileOffset, this.expression, this.cases) {
+    this.fileOffset = fileOffset;
+    expression.parent = this;
+    setParents(cases, this);
+  }
+
+  @override
+  StatementInferenceResult acceptInference(InferenceVisitorImpl visitor) {
+    return visitor.visitPatternSwitchStatement(this);
+  }
+
+  @override
+  String toString() {
+    return "PatternSwitchStatement(${toStringInternal()})";
+  }
+
+  @override
+  void toTextInternal(AstPrinter printer) {
+    printer.write('switch (');
+    printer.writeExpression(expression);
+    printer.write(') {');
+    printer.incIndentation();
+    for (SwitchCase switchCase in cases) {
+      printer.newLine();
+      printer.writeSwitchCase(switchCase);
+    }
+    printer.decIndentation();
+    printer.newLine();
+    printer.write('}');
+  }
+
+  @override
+  void transformChildren(Transformer v) {
+    throw new UnsupportedError('PatternSwitchStatement.transformChildren');
+  }
+
+  @override
+  void transformOrRemoveChildren(RemovingTransformer v) {
+    throw new UnsupportedError(
+        'PatternSwitchStatement.transformOrRemoveChildren');
+  }
+
+  @override
+  void visitChildren(Visitor v) {
+    throw new UnsupportedError('PatternSwitchStatement.visitChildren');
+  }
+}
+
 class BreakStatementImpl extends BreakStatement {
   Statement? targetStatement;
   final bool isContinue;
@@ -6182,17 +6318,15 @@ final Pattern dummyPattern = new ExpressionPattern(dummyExpression);
 ///
 class IfCaseStatement extends InternalStatement {
   Expression expression;
-  Pattern pattern;
-  Expression? guard;
+  PatternGuard patternGuard;
   Statement then;
   Statement? otherwise;
 
-  IfCaseStatement(this.expression, this.pattern, this.guard, this.then,
-      this.otherwise, int fileOffset) {
+  IfCaseStatement(this.expression, this.patternGuard, this.then, this.otherwise,
+      int fileOffset) {
     this.fileOffset = fileOffset;
     expression.parent = this;
-    pattern.parent = this;
-    guard?.parent = this;
+    patternGuard.parent = this;
     then.parent = this;
     otherwise?.parent = this;
   }
@@ -6207,11 +6341,7 @@ class IfCaseStatement extends InternalStatement {
     printer.write('if (');
     printer.writeExpression(expression);
     printer.write(' case ');
-    pattern.toTextInternal(printer);
-    if (guard != null) {
-      printer.write(' when ');
-      printer.writeExpression(guard!);
-    }
+    patternGuard.toTextInternal(printer);
     printer.write(') ');
     printer.writeStatement(then);
     if (otherwise != null) {
diff --git a/pkg/front_end/lib/src/fasta/source/diet_listener.dart b/pkg/front_end/lib/src/fasta/source/diet_listener.dart
index 465ad30f3b59f..6d20f5e595d4a 100644
--- a/pkg/front_end/lib/src/fasta/source/diet_listener.dart
+++ b/pkg/front_end/lib/src/fasta/source/diet_listener.dart
@@ -113,7 +113,7 @@ class DietListener extends StackListenerImpl {
 
   @override
   void endMetadataStar(int count) {
-    assert(checkState(null, repeatedKinds(ValueKinds.Token, count)));
+    assert(checkState(null, repeatedKind(ValueKinds.Token, count)));
     debugEvent("MetadataStar");
     if (count > 0) {
       discard(count - 1);
diff --git a/pkg/front_end/lib/src/fasta/source/outline_builder.dart b/pkg/front_end/lib/src/fasta/source/outline_builder.dart
index 09f71ed0091b7..05f43bcccd43c 100644
--- a/pkg/front_end/lib/src/fasta/source/outline_builder.dart
+++ b/pkg/front_end/lib/src/fasta/source/outline_builder.dart
@@ -2690,7 +2690,7 @@ class OutlineBuilder extends StackListenerImpl {
     debugEvent("RecordType");
     assert(checkState(leftBracket, [
       if (hasNamedFields) ValueKinds.RecordTypeFieldBuilderListOrNull,
-      ...repeatedKinds(ValueKinds.RecordTypeFieldBuilder,
+      ...repeatedKind(ValueKinds.RecordTypeFieldBuilder,
           hasNamedFields ? count - 1 : count),
     ]));
 
@@ -2759,7 +2759,7 @@ class OutlineBuilder extends StackListenerImpl {
   @override
   void endRecordTypeNamedFields(int count, Token leftBracket) {
     assert(checkState(leftBracket, [
-      ...repeatedKinds(ValueKinds.RecordTypeFieldBuilder, count),
+      ...repeatedKind(ValueKinds.RecordTypeFieldBuilder, count),
     ]));
     List<RecordTypeFieldBuilder>? fields =
         const FixedNullableList<RecordTypeFieldBuilder>()
diff --git a/pkg/front_end/lib/src/fasta/source/value_kinds.dart b/pkg/front_end/lib/src/fasta/source/value_kinds.dart
index 660abb078dbba..ed8df66494515 100644
--- a/pkg/front_end/lib/src/fasta/source/value_kinds.dart
+++ b/pkg/front_end/lib/src/fasta/source/value_kinds.dart
@@ -27,7 +27,7 @@ import '../builder/type_variable_builder.dart' as type;
 import '../identifiers.dart' as type;
 
 import '../kernel/body_builder.dart' as type
-    show Condition, FormalParameters, JumpTarget;
+    show Condition, FormalParameters, JumpTarget, Label;
 import '../kernel/expression_generator.dart' as type;
 import '../kernel/internal_ast.dart' as type;
 
@@ -64,6 +64,8 @@ class ValueKinds {
   static const ValueKind ContinueTarget =
       const SingleValueKind<type.JumpTarget>(NullValue.ContinueTarget);
   static const ValueKind Expression = const SingleValueKind<type.Expression>();
+  static const ValueKind ExpressionOrPatternGuardList =
+      const SingleValueKind<List<Object>>();
   static const ValueKind ExpressionOrNull =
       const SingleValueKind<type.Expression>(NullValue.Expression);
   static const ValueKind FieldInitializerOrNull =
@@ -82,11 +84,16 @@ class ValueKinds {
   static const ValueKind Initializer =
       const SingleValueKind<type.Initializer>();
   static const ValueKind Integer = const SingleValueKind<int>();
+  static const ValueKind Label = const SingleValueKind<type.Label>();
+  static const ValueKind LabelListOrNull =
+      const SingleValueKind<List<type.Label>>(NullValue.Labels);
   static const ValueKind MapLiteralEntry =
       const SingleValueKind<type.MapLiteralEntry>();
   static const ValueKind MapPatternEntry =
       const SingleValueKind<type.MapPatternEntry>();
   static const ValueKind Pattern = const SingleValueKind<type.Pattern>();
+  static const ValueKind PatternGuard =
+      const SingleValueKind<type.PatternGuard>();
   static const ValueKind PatternOrNull =
       const SingleValueKind<type.Pattern>(NullValue.Pattern);
   static const ValueKind PatternListOrNull =
@@ -139,6 +146,7 @@ class ValueKinds {
           NullValue.RecordTypeFieldList);
   static const ValueKind Scope = const SingleValueKind<type.Scope>();
   static const ValueKind Selector = const SingleValueKind<type.Selector>();
+  static const ValueKind SwitchCase = const SingleValueKind<type.SwitchCase>();
   static const ValueKind SwitchCaseList =
       const SingleValueKind<List<type.SwitchCase>>();
   static const ValueKind SwitchScopeOrNull =
diff --git a/pkg/front_end/lib/src/fasta/type_inference/inference_visitor.dart b/pkg/front_end/lib/src/fasta/type_inference/inference_visitor.dart
index 5f1ef578c355a..0118c3f447d2b 100644
--- a/pkg/front_end/lib/src/fasta/type_inference/inference_visitor.dart
+++ b/pkg/front_end/lib/src/fasta/type_inference/inference_visitor.dart
@@ -1749,8 +1749,13 @@ class InferenceVisitorImpl extends InferenceVisitorBase
 
   StatementInferenceResult visitIfCaseStatement(IfCaseStatement node) {
     // TODO(scheglov) Pass actual variables, not just `{}`.
-    DartType scrutineeType = analyzeIfCaseStatement(node, node.expression,
-        node.pattern, node.guard, node.then, node.otherwise, {});
+    DartType scrutineeType = analyzeIfCaseStatement(
+        node,
+        node.expression,
+        node.patternGuard.pattern,
+        node.patternGuard.guard,
+        node.then,
+        node.otherwise, {});
     // Stack: (Expression scrutinee, Expression guard, Statement ifTrue,
     //         Statement ifFalse)
     Statement? otherwise = node.otherwise;
@@ -1764,8 +1769,9 @@ class InferenceVisitorImpl extends InferenceVisitorBase
       then = node.then = (rewrite as Statement)..parent = node;
     }
     rewrite = popRewrite();
-    if (!identical(node.guard, rewrite)) {
-      node.guard = (rewrite as Expression)..parent = node;
+    if (!identical(node.patternGuard.guard, rewrite)) {
+      node.patternGuard.guard = (rewrite as Expression)
+        ..parent = node.patternGuard;
     }
     rewrite = popRewrite();
     if (!identical(node.expression, rewrite)) {
@@ -1775,13 +1781,14 @@ class InferenceVisitorImpl extends InferenceVisitorBase
     VariableDeclaration matchedExpressionVariable = engine.forest
         .createVariableDeclarationForValue(node.expression,
             type: scrutineeType);
-    PatternTransformationResult transformationResult = node.pattern.transform(
-        engine.forest
-            .createVariableGet(node.fileOffset, matchedExpressionVariable),
-        scrutineeType,
-        engine.forest
-            .createVariableGet(node.fileOffset, matchedExpressionVariable),
-        this);
+    PatternTransformationResult transformationResult = node.patternGuard.pattern
+        .transform(
+            engine.forest
+                .createVariableGet(node.fileOffset, matchedExpressionVariable),
+            scrutineeType,
+            engine.forest
+                .createVariableGet(node.fileOffset, matchedExpressionVariable),
+            this);
 
     // isPatternMatchingFailed: bool VAR = true;
     VariableDeclaration isPatternMatchingFailed = engine.forest
@@ -1811,7 +1818,7 @@ class InferenceVisitorImpl extends InferenceVisitorBase
     }
 
     List<Statement> replacementStatements;
-    if (node.pattern.declaredVariables.isEmpty) {
+    if (node.patternGuard.pattern.declaredVariables.isEmpty) {
       replacementStatements = [
         if (otherwise != null) patternMatchedSet,
         if (then is! Block || then.statements.isNotEmpty) then
@@ -1823,7 +1830,7 @@ class InferenceVisitorImpl extends InferenceVisitorBase
         // The block is created to avoid having variables with the same name in
         // the same scope.
         engine.forest.createBlock(node.fileOffset, node.fileOffset, [
-          ...node.pattern.declaredVariables,
+          ...node.patternGuard.pattern.declaredVariables,
           if (then is! Block || then.statements.isNotEmpty) then
         ])
       ];
@@ -7727,6 +7734,12 @@ class InferenceVisitorImpl extends InferenceVisitorBase
         : const StatementInferenceResult();
   }
 
+  StatementInferenceResult visitPatternSwitchStatement(
+      PatternSwitchStatement node) {
+    return new StatementInferenceResult.single(
+        new ExpressionStatement(new InvalidExpression('$node')));
+  }
+
   @override
   ExpressionInferenceResult visitSymbolLiteral(
       SymbolLiteral node, DartType typeContext) {
diff --git a/pkg/front_end/test/text_representation/internal_ast_text_representation_test.dart b/pkg/front_end/test/text_representation/internal_ast_text_representation_test.dart
index a3a1421f5d37c..c4a9d0907c389 100644
--- a/pkg/front_end/test/text_representation/internal_ast_text_representation_test.dart
+++ b/pkg/front_end/test/text_representation/internal_ast_text_representation_test.dart
@@ -127,6 +127,7 @@ void main() {
     _testRelationalMatcher();
     _testMapMatcher();
     _testIfCaseStatement();
+    _testPatternSwitchStatement();
   });
 }
 
@@ -297,6 +298,62 @@ switch (null) {
 switch (null) { case 0: case 1: return; case 2: default: return; }''');
 }
 
+void _testPatternSwitchStatement() {
+  Expression expression = new NullLiteral();
+  PatternGuard case0 =
+      new PatternGuard(new ExpressionPattern(new IntLiteral(0)));
+  PatternGuard case1 =
+      new PatternGuard(new ExpressionPattern(new IntLiteral(1)));
+  PatternGuard case2 = new PatternGuard(
+      new ExpressionPattern(new IntLiteral(2)), new IntLiteral(3));
+  Block emptyBlock = new Block([]);
+  Block returnBlock1 = new Block([new ReturnStatement()]);
+  Block returnBlock2 = new Block([new ReturnStatement()]);
+
+  testStatement(
+      new PatternSwitchStatement(TreeNode.noOffset, expression, [
+        new PatternSwitchCase(TreeNode.noOffset, [case0], emptyBlock,
+            isDefault: false, hasLabel: false)
+      ]),
+      '''
+switch (null) {
+  case 0:
+}''',
+      limited: '''
+switch (null) { case 0: }''');
+
+  testStatement(
+      new PatternSwitchStatement(TreeNode.noOffset, expression, [
+        new PatternSwitchCase(TreeNode.noOffset, [], emptyBlock,
+            hasLabel: false, isDefault: true)
+      ]),
+      '''
+switch (null) {
+  default:
+}''',
+      limited: '''
+switch (null) { default: }''');
+
+  testStatement(
+      new PatternSwitchStatement(TreeNode.noOffset, expression, [
+        new PatternSwitchCase(TreeNode.noOffset, [case0, case1], returnBlock1,
+            hasLabel: false, isDefault: false),
+        new PatternSwitchCase(TreeNode.noOffset, [case2], returnBlock2,
+            hasLabel: true, isDefault: true)
+      ]),
+      '''
+switch (null) {
+  case 0:
+  case 1:
+    return;
+  case 2 when 3:
+  default:
+    return;
+}''',
+      limited: '''
+switch (null) { case 0: case 1: return; case 2 when 3: default: return; }''');
+}
+
 void _testBreakStatementImpl() {
   WhileStatement whileStatement =
       new WhileStatement(new BoolLiteral(true), new Block([]));
@@ -1173,8 +1230,7 @@ void _testIfCaseStatement() {
   testStatement(
       new IfCaseStatement(
           new IntLiteral(0),
-          new ExpressionPattern(new IntLiteral(1)),
-          null,
+          new PatternGuard(new ExpressionPattern(new IntLiteral(1))),
           new ReturnStatement(),
           null,
           TreeNode.noOffset),
@@ -1184,8 +1240,7 @@ if (0 case 1) return;''');
   testStatement(
       new IfCaseStatement(
           new IntLiteral(0),
-          new ExpressionPattern(new IntLiteral(1)),
-          null,
+          new PatternGuard(new ExpressionPattern(new IntLiteral(1))),
           new ReturnStatement(new IntLiteral(2)),
           new ReturnStatement(new IntLiteral(3)),
           TreeNode.noOffset),
@@ -1195,8 +1250,8 @@ if (0 case 1) return 2; else return 3;''');
   testStatement(
       new IfCaseStatement(
           new IntLiteral(0),
-          new ExpressionPattern(new IntLiteral(1)),
-          new IntLiteral(2),
+          new PatternGuard(
+              new ExpressionPattern(new IntLiteral(1)), new IntLiteral(2)),
           new ReturnStatement(),
           null,
           TreeNode.noOffset),
@@ -1206,8 +1261,8 @@ if (0 case 1 when 2) return;''');
   testStatement(
       new IfCaseStatement(
           new IntLiteral(0),
-          new ExpressionPattern(new IntLiteral(1)),
-          new IntLiteral(2),
+          new PatternGuard(
+              new ExpressionPattern(new IntLiteral(1)), new IntLiteral(2)),
           new ReturnStatement(new IntLiteral(3)),
           new ReturnStatement(new IntLiteral(4)),
           TreeNode.noOffset),
diff --git a/pkg/front_end/testcases/general/empty_switch.dart b/pkg/front_end/testcases/general/empty_switch.dart
new file mode 100644
index 0000000000000..a7a7a36a212e2
--- /dev/null
+++ b/pkg/front_end/testcases/general/empty_switch.dart
@@ -0,0 +1,8 @@
+// Copyright (c) 2022, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+main() {
+  switch (1) {
+  }
+}
diff --git a/pkg/front_end/testcases/general/empty_switch.dart.textual_outline.expect b/pkg/front_end/testcases/general/empty_switch.dart.textual_outline.expect
new file mode 100644
index 0000000000000..bae895adcb685
--- /dev/null
+++ b/pkg/front_end/testcases/general/empty_switch.dart.textual_outline.expect
@@ -0,0 +1 @@
+main() {}
diff --git a/pkg/front_end/testcases/general/empty_switch.dart.textual_outline_modelled.expect b/pkg/front_end/testcases/general/empty_switch.dart.textual_outline_modelled.expect
new file mode 100644
index 0000000000000..bae895adcb685
--- /dev/null
+++ b/pkg/front_end/testcases/general/empty_switch.dart.textual_outline_modelled.expect
@@ -0,0 +1 @@
+main() {}
diff --git a/pkg/front_end/testcases/general/empty_switch.dart.weak.expect b/pkg/front_end/testcases/general/empty_switch.dart.weak.expect
new file mode 100644
index 0000000000000..9201d1e523036
--- /dev/null
+++ b/pkg/front_end/testcases/general/empty_switch.dart.weak.expect
@@ -0,0 +1,7 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+
+static method main() → dynamic {
+  switch(1) {
+  }
+}
diff --git a/pkg/front_end/testcases/general/empty_switch.dart.weak.modular.expect b/pkg/front_end/testcases/general/empty_switch.dart.weak.modular.expect
new file mode 100644
index 0000000000000..9201d1e523036
--- /dev/null
+++ b/pkg/front_end/testcases/general/empty_switch.dart.weak.modular.expect
@@ -0,0 +1,7 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+
+static method main() → dynamic {
+  switch(1) {
+  }
+}
diff --git a/pkg/front_end/testcases/general/empty_switch.dart.weak.outline.expect b/pkg/front_end/testcases/general/empty_switch.dart.weak.outline.expect
new file mode 100644
index 0000000000000..e2cba6be4d131
--- /dev/null
+++ b/pkg/front_end/testcases/general/empty_switch.dart.weak.outline.expect
@@ -0,0 +1,5 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+
+static method main() → dynamic
+  ;
diff --git a/pkg/front_end/testcases/general/empty_switch.dart.weak.transformed.expect b/pkg/front_end/testcases/general/empty_switch.dart.weak.transformed.expect
new file mode 100644
index 0000000000000..9201d1e523036
--- /dev/null
+++ b/pkg/front_end/testcases/general/empty_switch.dart.weak.transformed.expect
@@ -0,0 +1,7 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+
+static method main() → dynamic {
+  switch(1) {
+  }
+}
diff --git a/pkg/front_end/testcases/general/labeled_default.dart b/pkg/front_end/testcases/general/labeled_default.dart
new file mode 100644
index 0000000000000..f2de312b266ba
--- /dev/null
+++ b/pkg/front_end/testcases/general/labeled_default.dart
@@ -0,0 +1,10 @@
+// Copyright (c) 2022, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+main() {
+  switch (1) {
+    $:
+    default:
+  }
+}
diff --git a/pkg/front_end/testcases/general/labeled_default.dart.textual_outline.expect b/pkg/front_end/testcases/general/labeled_default.dart.textual_outline.expect
new file mode 100644
index 0000000000000..bae895adcb685
--- /dev/null
+++ b/pkg/front_end/testcases/general/labeled_default.dart.textual_outline.expect
@@ -0,0 +1 @@
+main() {}
diff --git a/pkg/front_end/testcases/general/labeled_default.dart.textual_outline_modelled.expect b/pkg/front_end/testcases/general/labeled_default.dart.textual_outline_modelled.expect
new file mode 100644
index 0000000000000..bae895adcb685
--- /dev/null
+++ b/pkg/front_end/testcases/general/labeled_default.dart.textual_outline_modelled.expect
@@ -0,0 +1 @@
+main() {}
diff --git a/pkg/front_end/testcases/general/labeled_default.dart.weak.expect b/pkg/front_end/testcases/general/labeled_default.dart.weak.expect
new file mode 100644
index 0000000000000..082de32259e51
--- /dev/null
+++ b/pkg/front_end/testcases/general/labeled_default.dart.weak.expect
@@ -0,0 +1,10 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+
+static method main() → dynamic {
+  switch(1) {
+    #L1:
+    default:
+      {}
+  }
+}
diff --git a/pkg/front_end/testcases/general/labeled_default.dart.weak.modular.expect b/pkg/front_end/testcases/general/labeled_default.dart.weak.modular.expect
new file mode 100644
index 0000000000000..082de32259e51
--- /dev/null
+++ b/pkg/front_end/testcases/general/labeled_default.dart.weak.modular.expect
@@ -0,0 +1,10 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+
+static method main() → dynamic {
+  switch(1) {
+    #L1:
+    default:
+      {}
+  }
+}
diff --git a/pkg/front_end/testcases/general/labeled_default.dart.weak.outline.expect b/pkg/front_end/testcases/general/labeled_default.dart.weak.outline.expect
new file mode 100644
index 0000000000000..e2cba6be4d131
--- /dev/null
+++ b/pkg/front_end/testcases/general/labeled_default.dart.weak.outline.expect
@@ -0,0 +1,5 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+
+static method main() → dynamic
+  ;
diff --git a/pkg/front_end/testcases/general/labeled_default.dart.weak.transformed.expect b/pkg/front_end/testcases/general/labeled_default.dart.weak.transformed.expect
new file mode 100644
index 0000000000000..082de32259e51
--- /dev/null
+++ b/pkg/front_end/testcases/general/labeled_default.dart.weak.transformed.expect
@@ -0,0 +1,10 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+
+static method main() → dynamic {
+  switch(1) {
+    #L1:
+    default:
+      {}
+  }
+}
diff --git a/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.strong.expect b/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.strong.expect
index c4a01a2fd5fcc..830df6d11fc56 100644
--- a/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case true as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.strong.transformed.expect
index c4a01a2fd5fcc..830df6d11fc56 100644
--- a/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case true as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.weak.expect b/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.weak.expect
index c4a01a2fd5fcc..830df6d11fc56 100644
--- a/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case true as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.weak.modular.expect
index c4a01a2fd5fcc..830df6d11fc56 100644
--- a/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case true as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.weak.transformed.expect
index c4a01a2fd5fcc..830df6d11fc56 100644
--- a/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/boolean_literal_inside_cast.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case true as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.strong.expect b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.strong.expect
index c4a01a2fd5fcc..354c8d70549e2 100644
--- a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case true!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.strong.transformed.expect
index c4a01a2fd5fcc..354c8d70549e2 100644
--- a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case true!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.weak.expect b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.weak.expect
index c4a01a2fd5fcc..354c8d70549e2 100644
--- a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case true!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.weak.modular.expect
index c4a01a2fd5fcc..354c8d70549e2 100644
--- a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case true!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.weak.transformed.expect
index c4a01a2fd5fcc..354c8d70549e2 100644
--- a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_assert.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case true!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.strong.expect b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.strong.expect
index c4a01a2fd5fcc..b3b990ff2f59a 100644
--- a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case true?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.strong.transformed.expect
index c4a01a2fd5fcc..b3b990ff2f59a 100644
--- a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case true?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.weak.expect b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.weak.expect
index c4a01a2fd5fcc..b3b990ff2f59a 100644
--- a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case true?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.weak.modular.expect
index c4a01a2fd5fcc..b3b990ff2f59a 100644
--- a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case true?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.weak.transformed.expect
index c4a01a2fd5fcc..b3b990ff2f59a 100644
--- a/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/boolean_literal_inside_null_check.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case true?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.strong.expect b/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.strong.expect
index 16472c4e5deed..fe7d0c3653de9 100644
--- a/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.strong.expect
@@ -1,18 +1,10 @@
 library /*isNonNullableByDefault*/;
 import self as self;
-import "dart:core" as core;
 
 static method f(dynamic x) → void {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = 0
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 0 when true:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.strong.transformed.expect
index 16472c4e5deed..fe7d0c3653de9 100644
--- a/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.strong.transformed.expect
@@ -1,18 +1,10 @@
 library /*isNonNullableByDefault*/;
 import self as self;
-import "dart:core" as core;
 
 static method f(dynamic x) → void {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = 0
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 0 when true:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.weak.expect b/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.weak.expect
index 16472c4e5deed..fe7d0c3653de9 100644
--- a/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.weak.expect
@@ -1,18 +1,10 @@
 library /*isNonNullableByDefault*/;
 import self as self;
-import "dart:core" as core;
 
 static method f(dynamic x) → void {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = 0
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 0 when true:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.weak.modular.expect
index 16472c4e5deed..fe7d0c3653de9 100644
--- a/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.weak.modular.expect
@@ -1,18 +1,10 @@
 library /*isNonNullableByDefault*/;
 import self as self;
-import "dart:core" as core;
 
 static method f(dynamic x) → void {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = 0
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 0 when true:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.weak.transformed.expect
index 16472c4e5deed..fe7d0c3653de9 100644
--- a/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/caseHead_withClassicPattern_guarded_insideSwitchStatement.dart.weak.transformed.expect
@@ -1,18 +1,10 @@
 library /*isNonNullableByDefault*/;
 import self as self;
-import "dart:core" as core;
 
 static method f(dynamic x) → void {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = 0
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 0 when true:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.strong.expect b/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.strong.expect
index 09c2ebb806016..50f291f65fd72 100644
--- a/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method f(dynamic x) → void {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 0 as int when true:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.strong.transformed.expect
index 09c2ebb806016..50f291f65fd72 100644
--- a/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method f(dynamic x) → void {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 0 as int when true:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.weak.expect b/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.weak.expect
index 09c2ebb806016..50f291f65fd72 100644
--- a/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method f(dynamic x) → void {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 0 as int when true:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.weak.modular.expect
index 09c2ebb806016..50f291f65fd72 100644
--- a/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method f(dynamic x) → void {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 0 as int when true:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.weak.transformed.expect
index 09c2ebb806016..50f291f65fd72 100644
--- a/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/caseHead_withNewPattern_guarded_insideSwitchStatement.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method f(dynamic x) → void {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 0 as int when true:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_case.dart.strong.expect b/pkg/front_end/testcases/patterns/cast_inside_case.dart.strong.expect
index c4a01a2fd5fcc..9f7bdbab45b4e 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_case.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_case.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y as int:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_case.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_case.dart.strong.transformed.expect
index c4a01a2fd5fcc..9f7bdbab45b4e 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_case.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_case.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y as int:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_case.dart.weak.expect b/pkg/front_end/testcases/patterns/cast_inside_case.dart.weak.expect
index c4a01a2fd5fcc..9f7bdbab45b4e 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_case.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_case.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y as int:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_case.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/cast_inside_case.dart.weak.modular.expect
index c4a01a2fd5fcc..9f7bdbab45b4e 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_case.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_case.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y as int:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_case.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_case.dart.weak.transformed.expect
index c4a01a2fd5fcc..9f7bdbab45b4e 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_case.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_case.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y as int:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.strong.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.strong.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.strong.transformed.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.strong.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.weak.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.weak.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.weak.modular.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.weak.modular.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.weak.transformed.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern.dart.weak.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.strong.expect b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.strong.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.strong.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.strong.transformed.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.strong.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.weak.expect b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.weak.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.weak.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.weak.modular.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.weak.modular.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.weak.transformed.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_extractor_pattern_implicitly_named.dart.weak.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.strong.expect
index c4a01a2fd5fcc..00525917ee864 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1 as int]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.strong.transformed.expect
index c4a01a2fd5fcc..00525917ee864 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1 as int]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.weak.expect
index c4a01a2fd5fcc..00525917ee864 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1 as int]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.weak.modular.expect
index c4a01a2fd5fcc..00525917ee864 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1 as int]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.weak.transformed.expect
index c4a01a2fd5fcc..00525917ee864 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_list_pattern.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1 as int]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.strong.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.strong.expect
index c4a01a2fd5fcc..57e8b6efbf349 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ as double? & Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..57e8b6efbf349 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ as double? & Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.weak.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.weak.expect
index c4a01a2fd5fcc..57e8b6efbf349 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ as double? & Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.weak.modular.expect
index c4a01a2fd5fcc..57e8b6efbf349 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ as double? & Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..57e8b6efbf349 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_and_lhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ as double? & Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.strong.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.strong.expect
index c4a01a2fd5fcc..bc1623ccbef64 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ & double? _ as Object?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..bc1623ccbef64 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ & double? _ as Object?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.weak.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.weak.expect
index c4a01a2fd5fcc..bc1623ccbef64 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ & double? _ as Object?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.weak.modular.expect
index c4a01a2fd5fcc..bc1623ccbef64 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ & double? _ as Object?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..bc1623ccbef64 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_and_rhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ & double? _ as Object?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.strong.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.strong.expect
index c4a01a2fd5fcc..9d8f70542dd09 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ as double? | Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..9d8f70542dd09 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ as double? | Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.weak.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.weak.expect
index c4a01a2fd5fcc..9d8f70542dd09 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ as double? | Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.weak.modular.expect
index c4a01a2fd5fcc..9d8f70542dd09 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ as double? | Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..9d8f70542dd09 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_or_lhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ as double? | Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.strong.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.strong.expect
index c4a01a2fd5fcc..da227aeae44f1 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ | double? _ as Object?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..da227aeae44f1 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ | double? _ as Object?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.weak.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.weak.expect
index c4a01a2fd5fcc..da227aeae44f1 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ | double? _ as Object?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.weak.modular.expect
index c4a01a2fd5fcc..da227aeae44f1 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ | double? _ as Object?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..da227aeae44f1 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_logical_or_rhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ | double? _ as Object?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.strong.expect
index c4a01a2fd5fcc..2d32bd0f54801 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1 as int}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.strong.transformed.expect
index c4a01a2fd5fcc..2d32bd0f54801 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1 as int}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.weak.expect
index c4a01a2fd5fcc..2d32bd0f54801 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1 as int}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.weak.modular.expect
index c4a01a2fd5fcc..2d32bd0f54801 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1 as int}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.weak.transformed.expect
index c4a01a2fd5fcc..2d32bd0f54801 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_map_pattern.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1 as int}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.strong.expect
index c4a01a2fd5fcc..5ede2964a580c 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 as int:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.strong.transformed.expect
index c4a01a2fd5fcc..5ede2964a580c 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 as int:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.weak.expect
index c4a01a2fd5fcc..5ede2964a580c 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 as int:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.weak.modular.expect
index c4a01a2fd5fcc..5ede2964a580c 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 as int:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.weak.transformed.expect
index c4a01a2fd5fcc..5ede2964a580c 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_parenthesized_pattern.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 as int:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.strong.expect b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.strong.expect
index c4a01a2fd5fcc..fcad02a6211fd 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: var n as int, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.strong.transformed.expect
index c4a01a2fd5fcc..fcad02a6211fd 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: var n as int, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.weak.expect b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.weak.expect
index c4a01a2fd5fcc..fcad02a6211fd 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: var n as int, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.weak.modular.expect
index c4a01a2fd5fcc..fcad02a6211fd 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: var n as int, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.weak.transformed.expect
index c4a01a2fd5fcc..fcad02a6211fd 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_implicitly_named.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: var n as int, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.strong.expect b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.strong.expect
index c4a01a2fd5fcc..82b1a1e163ed8 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: 1 as int, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.strong.transformed.expect
index c4a01a2fd5fcc..82b1a1e163ed8 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: 1 as int, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.weak.expect b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.weak.expect
index c4a01a2fd5fcc..82b1a1e163ed8 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: 1 as int, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.weak.modular.expect
index c4a01a2fd5fcc..82b1a1e163ed8 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: 1 as int, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.weak.transformed.expect
index c4a01a2fd5fcc..82b1a1e163ed8 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_named.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: 1 as int, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.strong.expect b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.strong.expect
index c4a01a2fd5fcc..24e9ab6001786 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1 as int, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.strong.transformed.expect
index c4a01a2fd5fcc..24e9ab6001786 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1 as int, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.weak.expect b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.weak.expect
index c4a01a2fd5fcc..24e9ab6001786 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1 as int, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.weak.modular.expect
index c4a01a2fd5fcc..24e9ab6001786 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1 as int, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.weak.transformed.expect
index c4a01a2fd5fcc..24e9ab6001786 100644
--- a/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/cast_inside_record_pattern_unnamed.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1 as int, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.strong.expect b/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.strong.expect
index c4a01a2fd5fcc..0d730184e83cb 100644
--- a/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.strong.transformed.expect
index c4a01a2fd5fcc..0d730184e83cb 100644
--- a/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.weak.expect b/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.weak.expect
index c4a01a2fd5fcc..0d730184e83cb 100644
--- a/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.weak.modular.expect
index c4a01a2fd5fcc..0d730184e83cb 100644
--- a/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.weak.transformed.expect
index c4a01a2fd5fcc..0d730184e83cb 100644
--- a/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/constant_identifier_inside_cast.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.strong.expect b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.strong.expect
index c4a01a2fd5fcc..1c6d3be3f0c2d 100644
--- a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.strong.transformed.expect
index c4a01a2fd5fcc..1c6d3be3f0c2d 100644
--- a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.weak.expect b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.weak.expect
index c4a01a2fd5fcc..1c6d3be3f0c2d 100644
--- a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.weak.modular.expect
index c4a01a2fd5fcc..1c6d3be3f0c2d 100644
--- a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.weak.transformed.expect
index c4a01a2fd5fcc..1c6d3be3f0c2d 100644
--- a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_assert.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.strong.expect b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.strong.expect
index c4a01a2fd5fcc..96b3d749cdd73 100644
--- a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.strong.transformed.expect
index c4a01a2fd5fcc..96b3d749cdd73 100644
--- a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.weak.expect b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.weak.expect
index c4a01a2fd5fcc..96b3d749cdd73 100644
--- a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.weak.modular.expect
index c4a01a2fd5fcc..96b3d749cdd73 100644
--- a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.weak.transformed.expect
index c4a01a2fd5fcc..96b3d749cdd73 100644
--- a/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/constant_identifier_inside_null_check.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.strong.expect b/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.strong.expect
index c4a01a2fd5fcc..4028c7d5a6ac7 100644
--- a/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1.0 as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.strong.transformed.expect
index c4a01a2fd5fcc..4028c7d5a6ac7 100644
--- a/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1.0 as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.weak.expect b/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.weak.expect
index c4a01a2fd5fcc..4028c7d5a6ac7 100644
--- a/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1.0 as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.weak.modular.expect
index c4a01a2fd5fcc..4028c7d5a6ac7 100644
--- a/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1.0 as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.weak.transformed.expect
index c4a01a2fd5fcc..4028c7d5a6ac7 100644
--- a/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/double_literal_inside_cast.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1.0 as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.strong.expect b/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.strong.expect
index c4a01a2fd5fcc..a38e720730c19 100644
--- a/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1.0!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.strong.transformed.expect
index c4a01a2fd5fcc..a38e720730c19 100644
--- a/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1.0!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.weak.expect b/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.weak.expect
index c4a01a2fd5fcc..a38e720730c19 100644
--- a/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1.0!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.weak.modular.expect
index c4a01a2fd5fcc..a38e720730c19 100644
--- a/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1.0!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.weak.transformed.expect
index c4a01a2fd5fcc..a38e720730c19 100644
--- a/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/double_literal_inside_null_assert.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1.0!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.strong.expect b/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.strong.expect
index c4a01a2fd5fcc..d67f5e44f7dbf 100644
--- a/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1.0?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.strong.transformed.expect
index c4a01a2fd5fcc..d67f5e44f7dbf 100644
--- a/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1.0?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.weak.expect b/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.weak.expect
index c4a01a2fd5fcc..d67f5e44f7dbf 100644
--- a/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1.0?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.weak.modular.expect
index c4a01a2fd5fcc..d67f5e44f7dbf 100644
--- a/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1.0?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.weak.transformed.expect
index c4a01a2fd5fcc..d67f5e44f7dbf 100644
--- a/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/double_literal_inside_null_check.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1.0?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.strong.expect b/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.strong.expect
index 9c70e8d02e902..17720ddb74c87 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.strong.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern> as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.strong.transformed.expect
index 9c70e8d02e902..17720ddb74c87 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.strong.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern> as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.weak.expect b/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.weak.expect
index 9c70e8d02e902..17720ddb74c87 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.weak.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern> as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.weak.modular.expect
index 9c70e8d02e902..17720ddb74c87 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.weak.modular.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern> as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.weak.transformed.expect
index 9c70e8d02e902..17720ddb74c87 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_inside_cast.dart.weak.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern> as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.strong.expect b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.strong.expect
index 9c70e8d02e902..7e80889266217 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.strong.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.strong.transformed.expect
index 9c70e8d02e902..7e80889266217 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.strong.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.weak.expect b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.weak.expect
index 9c70e8d02e902..7e80889266217 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.weak.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.weak.modular.expect
index 9c70e8d02e902..7e80889266217 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.weak.modular.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.weak.transformed.expect
index 9c70e8d02e902..7e80889266217 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_assert.dart.weak.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.strong.expect b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.strong.expect
index 9c70e8d02e902..74e84ad165018 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.strong.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.strong.transformed.expect
index 9c70e8d02e902..74e84ad165018 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.strong.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.weak.expect b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.weak.expect
index 9c70e8d02e902..74e84ad165018 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.weak.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.weak.modular.expect
index 9c70e8d02e902..74e84ad165018 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.weak.modular.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.weak.transformed.expect
index 9c70e8d02e902..74e84ad165018 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_inside_null_check.dart.weak.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.strong.expect b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.strong.expect
index f51de1235ccae..89fb8f586c396 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.strong.expect
@@ -9,15 +9,8 @@ class C<T extends core::Object? = dynamic> extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.strong.transformed.expect
index f51de1235ccae..89fb8f586c396 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.strong.transformed.expect
@@ -9,15 +9,8 @@ class C<T extends core::Object? = dynamic> extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.weak.expect b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.weak.expect
index f51de1235ccae..89fb8f586c396 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.weak.expect
@@ -9,15 +9,8 @@ class C<T extends core::Object? = dynamic> extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.weak.modular.expect
index f51de1235ccae..89fb8f586c396 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.weak.modular.expect
@@ -9,15 +9,8 @@ class C<T extends core::Object? = dynamic> extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.weak.transformed.expect
index f51de1235ccae..89fb8f586c396 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args.dart.weak.transformed.expect
@@ -9,15 +9,8 @@ class C<T extends core::Object? = dynamic> extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.strong.expect b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.strong.expect
index 918a402d9296b..64b8b33e573d5 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.strong.expect
@@ -10,15 +10,8 @@ class C<T extends core::Object? = dynamic> extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.strong.transformed.expect
index 918a402d9296b..64b8b33e573d5 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.strong.transformed.expect
@@ -10,15 +10,8 @@ class C<T extends core::Object? = dynamic> extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.weak.expect b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.weak.expect
index 918a402d9296b..64b8b33e573d5 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.weak.expect
@@ -10,15 +10,8 @@ class C<T extends core::Object? = dynamic> extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.weak.modular.expect
index 918a402d9296b..64b8b33e573d5 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.weak.modular.expect
@@ -10,15 +10,8 @@ class C<T extends core::Object? = dynamic> extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.weak.transformed.expect
index 918a402d9296b..64b8b33e573d5 100644
--- a/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/extractor_pattern_with_type_args_inside_null_assert.dart.weak.transformed.expect
@@ -10,15 +10,8 @@ class C<T extends core::Object? = dynamic> extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.strong.expect b/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.strong.expect
index c4a01a2fd5fcc..2931fd83041f3 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.strong.transformed.expect
index c4a01a2fd5fcc..2931fd83041f3 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.weak.expect b/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.weak.expect
index c4a01a2fd5fcc..2931fd83041f3 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.weak.modular.expect
index c4a01a2fd5fcc..2931fd83041f3 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.weak.transformed.expect
index c4a01a2fd5fcc..2931fd83041f3 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_case.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.strong.expect b/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.strong.expect
index c4a01a2fd5fcc..3b256661485b3 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.strong.transformed.expect
index c4a01a2fd5fcc..3b256661485b3 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.weak.expect b/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.weak.expect
index c4a01a2fd5fcc..3b256661485b3 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.weak.modular.expect
index c4a01a2fd5fcc..3b256661485b3 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.weak.transformed.expect
index c4a01a2fd5fcc..3b256661485b3 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_cast.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.strong.expect b/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.strong.expect
index c4a01a2fd5fcc..0ef002717808b 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.strong.transformed.expect
index c4a01a2fd5fcc..0ef002717808b 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.weak.expect b/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.weak.expect
index c4a01a2fd5fcc..0ef002717808b 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.weak.modular.expect
index c4a01a2fd5fcc..0ef002717808b 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.weak.transformed.expect
index c4a01a2fd5fcc..0ef002717808b 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_null_assert.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.strong.expect b/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.strong.expect
index c4a01a2fd5fcc..dfe66ea1dc012 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.strong.transformed.expect
index c4a01a2fd5fcc..dfe66ea1dc012 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.weak.expect b/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.weak.expect
index c4a01a2fd5fcc..dfe66ea1dc012 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.weak.modular.expect
index c4a01a2fd5fcc..dfe66ea1dc012 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.weak.transformed.expect
index c4a01a2fd5fcc..dfe66ea1dc012 100644
--- a/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/final_variable_inside_null_check.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.strong.expect b/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.strong.expect
index c4a01a2fd5fcc..96046d87ebf3f 100644
--- a/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.strong.transformed.expect
index c4a01a2fd5fcc..96046d87ebf3f 100644
--- a/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.weak.expect b/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.weak.expect
index c4a01a2fd5fcc..96046d87ebf3f 100644
--- a/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.weak.modular.expect
index c4a01a2fd5fcc..96046d87ebf3f 100644
--- a/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.weak.transformed.expect
index c4a01a2fd5fcc..96046d87ebf3f 100644
--- a/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/integer_literal_inside_cast.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.strong.expect b/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.strong.expect
index c4a01a2fd5fcc..08fa512a5011f 100644
--- a/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.strong.transformed.expect
index c4a01a2fd5fcc..08fa512a5011f 100644
--- a/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.weak.expect b/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.weak.expect
index c4a01a2fd5fcc..08fa512a5011f 100644
--- a/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.weak.modular.expect
index c4a01a2fd5fcc..08fa512a5011f 100644
--- a/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.weak.transformed.expect
index c4a01a2fd5fcc..08fa512a5011f 100644
--- a/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/integer_literal_inside_null_assert.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.strong.expect b/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.strong.expect
index c4a01a2fd5fcc..51f0daf892f2c 100644
--- a/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.strong.transformed.expect
index c4a01a2fd5fcc..51f0daf892f2c 100644
--- a/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.weak.expect b/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.weak.expect
index c4a01a2fd5fcc..51f0daf892f2c 100644
--- a/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.weak.modular.expect
index c4a01a2fd5fcc..51f0daf892f2c 100644
--- a/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.weak.transformed.expect
index c4a01a2fd5fcc..51f0daf892f2c 100644
--- a/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/integer_literal_inside_null_check.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.strong.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.strong.expect
index c4a01a2fd5fcc..dec23e706ecea 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1, 2]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.strong.transformed.expect
index c4a01a2fd5fcc..dec23e706ecea 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1, 2]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.weak.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.weak.expect
index c4a01a2fd5fcc..dec23e706ecea 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1, 2]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.weak.modular.expect
index c4a01a2fd5fcc..dec23e706ecea 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1, 2]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.weak.transformed.expect
index c4a01a2fd5fcc..dec23e706ecea 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1, 2]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.strong.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.strong.expect
index c4a01a2fd5fcc..3e8cb36012a79 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.strong.transformed.expect
index c4a01a2fd5fcc..3e8cb36012a79 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.weak.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.weak.expect
index c4a01a2fd5fcc..3e8cb36012a79 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.weak.modular.expect
index c4a01a2fd5fcc..3e8cb36012a79 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.weak.transformed.expect
index c4a01a2fd5fcc..3e8cb36012a79 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.strong.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.strong.expect
index c4a01a2fd5fcc..3e8cb36012a79 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.strong.transformed.expect
index c4a01a2fd5fcc..3e8cb36012a79 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.weak.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.weak.expect
index c4a01a2fd5fcc..3e8cb36012a79 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.weak.modular.expect
index c4a01a2fd5fcc..3e8cb36012a79 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.weak.transformed.expect
index c4a01a2fd5fcc..3e8cb36012a79 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case_empty_whitespace.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.strong.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.strong.expect
index c4a01a2fd5fcc..b8a0304a12c7e 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <int>[1, 2]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.strong.transformed.expect
index c4a01a2fd5fcc..b8a0304a12c7e 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <int>[1, 2]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.weak.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.weak.expect
index c4a01a2fd5fcc..b8a0304a12c7e 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <int>[1, 2]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.weak.modular.expect
index c4a01a2fd5fcc..b8a0304a12c7e 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <int>[1, 2]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.weak.transformed.expect
index c4a01a2fd5fcc..b8a0304a12c7e 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_case_with_type_arguments.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <int>[1, 2]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.strong.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.strong.expect
index c4a01a2fd5fcc..12c80b38e315b 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1] as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.strong.transformed.expect
index c4a01a2fd5fcc..12c80b38e315b 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1] as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.weak.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.weak.expect
index c4a01a2fd5fcc..12c80b38e315b 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1] as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.weak.modular.expect
index c4a01a2fd5fcc..12c80b38e315b 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1] as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.weak.transformed.expect
index c4a01a2fd5fcc..12c80b38e315b 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_cast.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1] as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.strong.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.strong.expect
index c4a01a2fd5fcc..b76a277a84d67 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1]!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.strong.transformed.expect
index c4a01a2fd5fcc..b76a277a84d67 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1]!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.weak.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.weak.expect
index c4a01a2fd5fcc..b76a277a84d67 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1]!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.weak.modular.expect
index c4a01a2fd5fcc..b76a277a84d67 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1]!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.weak.transformed.expect
index c4a01a2fd5fcc..b76a277a84d67 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_null_assert.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1]!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.strong.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.strong.expect
index c4a01a2fd5fcc..4ca7226281b15 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1]?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.strong.transformed.expect
index c4a01a2fd5fcc..4ca7226281b15 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1]?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.weak.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.weak.expect
index c4a01a2fd5fcc..4ca7226281b15 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1]?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.weak.modular.expect
index c4a01a2fd5fcc..4ca7226281b15 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1]?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.weak.transformed.expect
index c4a01a2fd5fcc..4ca7226281b15 100644
--- a/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/list_pattern_inside_null_check.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1]?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.strong.expect b/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.strong.expect
index c4a01a2fd5fcc..d74f6d65860c4 100644
--- a/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ & double? _ & Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..d74f6d65860c4 100644
--- a/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ & double? _ & Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.weak.expect b/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.weak.expect
index c4a01a2fd5fcc..d74f6d65860c4 100644
--- a/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ & double? _ & Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.weak.modular.expect
index c4a01a2fd5fcc..d74f6d65860c4 100644
--- a/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ & double? _ & Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..d74f6d65860c4 100644
--- a/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/logical_and_inside_logical_and_lhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ & double? _ & Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.strong.expect b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.strong.expect
index c4a01a2fd5fcc..ec2a55d3384a5 100644
--- a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ & double? _ | Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..ec2a55d3384a5 100644
--- a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ & double? _ | Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.weak.expect b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.weak.expect
index c4a01a2fd5fcc..ec2a55d3384a5 100644
--- a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ & double? _ | Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.weak.modular.expect
index c4a01a2fd5fcc..ec2a55d3384a5 100644
--- a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ & double? _ | Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..ec2a55d3384a5 100644
--- a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_lhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ & double? _ | Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.strong.expect b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.strong.expect
index c4a01a2fd5fcc..e06d3f3dcc370 100644
--- a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ | double? _ & Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..e06d3f3dcc370 100644
--- a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ | double? _ & Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.weak.expect b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.weak.expect
index c4a01a2fd5fcc..e06d3f3dcc370 100644
--- a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ | double? _ & Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.weak.modular.expect
index c4a01a2fd5fcc..e06d3f3dcc370 100644
--- a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ | double? _ & Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..e06d3f3dcc370 100644
--- a/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/logical_and_inside_logical_or_rhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ | double? _ & Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.strong.expect b/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.strong.expect
index c4a01a2fd5fcc..23cbc89ed331c 100644
--- a/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ | double? _ | Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..23cbc89ed331c 100644
--- a/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ | double? _ | Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.weak.expect b/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.weak.expect
index c4a01a2fd5fcc..23cbc89ed331c 100644
--- a/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ | double? _ | Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.weak.modular.expect
index c4a01a2fd5fcc..23cbc89ed331c 100644
--- a/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ | double? _ | Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..23cbc89ed331c 100644
--- a/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/logical_or_inside_logical_or_lhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int? _ | double? _ | Object? _:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.strong.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.strong.expect
index c4a01a2fd5fcc..1f10916cef49a 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1, \"b\": 2}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.strong.transformed.expect
index c4a01a2fd5fcc..1f10916cef49a 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1, \"b\": 2}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.weak.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.weak.expect
index c4a01a2fd5fcc..1f10916cef49a 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1, \"b\": 2}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.weak.modular.expect
index c4a01a2fd5fcc..1f10916cef49a 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1, \"b\": 2}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.weak.transformed.expect
index c4a01a2fd5fcc..1f10916cef49a 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_case.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1, \"b\": 2}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.strong.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.strong.expect
index c4a01a2fd5fcc..7d9d78abb16de 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.strong.transformed.expect
index c4a01a2fd5fcc..7d9d78abb16de 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.weak.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.weak.expect
index c4a01a2fd5fcc..7d9d78abb16de 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.weak.modular.expect
index c4a01a2fd5fcc..7d9d78abb16de 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.weak.transformed.expect
index c4a01a2fd5fcc..7d9d78abb16de 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_case_empty.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.strong.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.strong.expect
index c4a01a2fd5fcc..5b91f18529fdf 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <String, int>{\"a\": 1, \"b\": 2}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.strong.transformed.expect
index c4a01a2fd5fcc..5b91f18529fdf 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <String, int>{\"a\": 1, \"b\": 2}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.weak.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.weak.expect
index c4a01a2fd5fcc..5b91f18529fdf 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <String, int>{\"a\": 1, \"b\": 2}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.weak.modular.expect
index c4a01a2fd5fcc..5b91f18529fdf 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <String, int>{\"a\": 1, \"b\": 2}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.weak.transformed.expect
index c4a01a2fd5fcc..5b91f18529fdf 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_case_with_type_arguments.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <String, int>{\"a\": 1, \"b\": 2}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.strong.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.strong.expect
index c4a01a2fd5fcc..304ccdc4a1f3e 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1} as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.strong.transformed.expect
index c4a01a2fd5fcc..304ccdc4a1f3e 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1} as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.weak.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.weak.expect
index c4a01a2fd5fcc..304ccdc4a1f3e 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1} as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.weak.modular.expect
index c4a01a2fd5fcc..304ccdc4a1f3e 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1} as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.weak.transformed.expect
index c4a01a2fd5fcc..304ccdc4a1f3e 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_cast.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1} as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.strong.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.strong.expect
index c4a01a2fd5fcc..8ba811277cb8c 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1}!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.strong.transformed.expect
index c4a01a2fd5fcc..8ba811277cb8c 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1}!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.weak.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.weak.expect
index c4a01a2fd5fcc..8ba811277cb8c 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1}!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.weak.modular.expect
index c4a01a2fd5fcc..8ba811277cb8c 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1}!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.weak.transformed.expect
index c4a01a2fd5fcc..8ba811277cb8c 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_null_assert.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1}!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.strong.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.strong.expect
index c4a01a2fd5fcc..28c0746ced4f8 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1}?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.strong.transformed.expect
index c4a01a2fd5fcc..28c0746ced4f8 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1}?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.weak.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.weak.expect
index c4a01a2fd5fcc..28c0746ced4f8 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1}?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.weak.modular.expect
index c4a01a2fd5fcc..28c0746ced4f8 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1}?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.weak.transformed.expect
index c4a01a2fd5fcc..28c0746ced4f8 100644
--- a/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/map_pattern_inside_null_check.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1}?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.strong.expect b/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.strong.expect
index c4a01a2fd5fcc..1c6d3be3f0c2d 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.strong.transformed.expect
index c4a01a2fd5fcc..1c6d3be3f0c2d 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.weak.expect b/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.weak.expect
index c4a01a2fd5fcc..1c6d3be3f0c2d 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.weak.modular.expect
index c4a01a2fd5fcc..1c6d3be3f0c2d 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.weak.transformed.expect
index c4a01a2fd5fcc..1c6d3be3f0c2d 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_case.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.strong.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.strong.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.strong.transformed.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.strong.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.weak.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.weak.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.weak.modular.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.weak.modular.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.weak.transformed.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern.dart.weak.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.strong.expect b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.strong.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.strong.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.strong.transformed.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.strong.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.weak.expect b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.weak.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.weak.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.weak.modular.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.weak.modular.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.weak.transformed.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_extractor_pattern_implicitly_named.dart.weak.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.strong.expect
index c4a01a2fd5fcc..fd65a11f5d866 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1!]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.strong.transformed.expect
index c4a01a2fd5fcc..fd65a11f5d866 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1!]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.weak.expect
index c4a01a2fd5fcc..fd65a11f5d866 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1!]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.weak.modular.expect
index c4a01a2fd5fcc..fd65a11f5d866 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1!]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.weak.transformed.expect
index c4a01a2fd5fcc..fd65a11f5d866 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_list_pattern.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1!]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.strong.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.strong.expect
index c4a01a2fd5fcc..76979dc0090d1 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1! & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..76979dc0090d1 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1! & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.weak.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.weak.expect
index c4a01a2fd5fcc..76979dc0090d1 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1! & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.weak.modular.expect
index c4a01a2fd5fcc..76979dc0090d1 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1! & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..76979dc0090d1 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_lhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1! & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.strong.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.strong.expect
index c4a01a2fd5fcc..a60174a756222 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & 2!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..a60174a756222 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & 2!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.weak.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.weak.expect
index c4a01a2fd5fcc..a60174a756222 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & 2!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.weak.modular.expect
index c4a01a2fd5fcc..a60174a756222 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & 2!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..a60174a756222 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_and_rhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & 2!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.strong.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.strong.expect
index c4a01a2fd5fcc..c4f5723636de0 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1! | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..c4f5723636de0 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1! | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.weak.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.weak.expect
index c4a01a2fd5fcc..c4f5723636de0 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1! | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.weak.modular.expect
index c4a01a2fd5fcc..c4f5723636de0 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1! | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..c4f5723636de0 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_lhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1! | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.strong.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.strong.expect
index c4a01a2fd5fcc..a468ac72ad09b 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | 2!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..a468ac72ad09b 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | 2!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.weak.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.weak.expect
index c4a01a2fd5fcc..a468ac72ad09b 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | 2!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.weak.modular.expect
index c4a01a2fd5fcc..a468ac72ad09b 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | 2!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..a468ac72ad09b 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_logical_or_rhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | 2!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.strong.expect
index c4a01a2fd5fcc..0a37f1f8dd2f2 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1!}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.strong.transformed.expect
index c4a01a2fd5fcc..0a37f1f8dd2f2 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1!}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.weak.expect
index c4a01a2fd5fcc..0a37f1f8dd2f2 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1!}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.weak.modular.expect
index c4a01a2fd5fcc..0a37f1f8dd2f2 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1!}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.weak.transformed.expect
index c4a01a2fd5fcc..0a37f1f8dd2f2 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_map_pattern.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1!}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.strong.expect
index c4a01a2fd5fcc..08fa512a5011f 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.strong.transformed.expect
index c4a01a2fd5fcc..08fa512a5011f 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.weak.expect
index c4a01a2fd5fcc..08fa512a5011f 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.weak.modular.expect
index c4a01a2fd5fcc..08fa512a5011f 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.weak.transformed.expect
index c4a01a2fd5fcc..08fa512a5011f 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_parenthesized_pattern.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.strong.expect b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.strong.expect
index c4a01a2fd5fcc..e804a3d088cce 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: var n!, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.strong.transformed.expect
index c4a01a2fd5fcc..e804a3d088cce 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: var n!, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.weak.expect b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.weak.expect
index c4a01a2fd5fcc..e804a3d088cce 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: var n!, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.weak.modular.expect
index c4a01a2fd5fcc..e804a3d088cce 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: var n!, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.weak.transformed.expect
index c4a01a2fd5fcc..e804a3d088cce 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_implicitly_named.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: var n!, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.strong.expect b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.strong.expect
index c4a01a2fd5fcc..e9f9efe1f5b30 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: 1!, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.strong.transformed.expect
index c4a01a2fd5fcc..e9f9efe1f5b30 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: 1!, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.weak.expect b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.weak.expect
index c4a01a2fd5fcc..e9f9efe1f5b30 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: 1!, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.weak.modular.expect
index c4a01a2fd5fcc..e9f9efe1f5b30 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: 1!, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.weak.transformed.expect
index c4a01a2fd5fcc..e9f9efe1f5b30 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_named.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: 1!, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.strong.expect b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.strong.expect
index c4a01a2fd5fcc..1d36db7a510b7 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1!, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.strong.transformed.expect
index c4a01a2fd5fcc..1d36db7a510b7 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1!, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.weak.expect b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.weak.expect
index c4a01a2fd5fcc..1d36db7a510b7 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1!, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.weak.modular.expect
index c4a01a2fd5fcc..1d36db7a510b7 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1!, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.weak.transformed.expect
index c4a01a2fd5fcc..1d36db7a510b7 100644
--- a/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_assert_inside_record_pattern_unnamed.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1!, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_case.dart.strong.expect b/pkg/front_end/testcases/patterns/null_check_inside_case.dart.strong.expect
index c4a01a2fd5fcc..96b3d749cdd73 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_case.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_case.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_case.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_case.dart.strong.transformed.expect
index c4a01a2fd5fcc..96b3d749cdd73 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_case.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_case.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_case.dart.weak.expect b/pkg/front_end/testcases/patterns/null_check_inside_case.dart.weak.expect
index c4a01a2fd5fcc..96b3d749cdd73 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_case.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_case.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_case.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_check_inside_case.dart.weak.modular.expect
index c4a01a2fd5fcc..96b3d749cdd73 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_case.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_case.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_case.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_case.dart.weak.transformed.expect
index c4a01a2fd5fcc..96b3d749cdd73 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_case.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_case.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.strong.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.strong.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.strong.transformed.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.strong.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.weak.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.weak.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.weak.modular.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.weak.modular.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.weak.transformed.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern.dart.weak.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.strong.expect b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.strong.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.strong.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.strong.transformed.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.strong.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.weak.expect b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.weak.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.weak.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.weak.modular.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.weak.modular.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.weak.transformed.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_extractor_pattern_implicitly_named.dart.weak.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.strong.expect
index c4a01a2fd5fcc..2793144331e55 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1?]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.strong.transformed.expect
index c4a01a2fd5fcc..2793144331e55 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1?]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.weak.expect
index c4a01a2fd5fcc..2793144331e55 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1?]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.weak.modular.expect
index c4a01a2fd5fcc..2793144331e55 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1?]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.weak.transformed.expect
index c4a01a2fd5fcc..2793144331e55 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_list_pattern.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[1?]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.strong.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.strong.expect
index c4a01a2fd5fcc..dba8dd6bc26a1 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1? & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..dba8dd6bc26a1 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1? & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.weak.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.weak.expect
index c4a01a2fd5fcc..dba8dd6bc26a1 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1? & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.weak.modular.expect
index c4a01a2fd5fcc..dba8dd6bc26a1 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1? & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..dba8dd6bc26a1 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_lhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1? & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.strong.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.strong.expect
index c4a01a2fd5fcc..029edc73fac4b 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & 2?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..029edc73fac4b 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & 2?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.weak.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.weak.expect
index c4a01a2fd5fcc..029edc73fac4b 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & 2?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.weak.modular.expect
index c4a01a2fd5fcc..029edc73fac4b 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & 2?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..029edc73fac4b 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_and_rhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & 2?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.strong.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.strong.expect
index c4a01a2fd5fcc..92b6f95b292e2 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1? | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..92b6f95b292e2 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1? | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.weak.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.weak.expect
index c4a01a2fd5fcc..92b6f95b292e2 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1? | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.weak.modular.expect
index c4a01a2fd5fcc..92b6f95b292e2 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1? | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..92b6f95b292e2 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_lhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1? | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.strong.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.strong.expect
index c4a01a2fd5fcc..ebf55a2fd4404 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | 2?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..ebf55a2fd4404 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | 2?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.weak.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.weak.expect
index c4a01a2fd5fcc..ebf55a2fd4404 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | 2?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.weak.modular.expect
index c4a01a2fd5fcc..ebf55a2fd4404 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | 2?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..ebf55a2fd4404 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_logical_or_rhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | 2?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.strong.expect
index c4a01a2fd5fcc..dde53b47b8764 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1?}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.strong.transformed.expect
index c4a01a2fd5fcc..dde53b47b8764 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1?}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.weak.expect
index c4a01a2fd5fcc..dde53b47b8764 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1?}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.weak.modular.expect
index c4a01a2fd5fcc..dde53b47b8764 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1?}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.weak.transformed.expect
index c4a01a2fd5fcc..dde53b47b8764 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_map_pattern.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": 1?}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.strong.expect
index c4a01a2fd5fcc..51f0daf892f2c 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.strong.transformed.expect
index c4a01a2fd5fcc..51f0daf892f2c 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.weak.expect
index c4a01a2fd5fcc..51f0daf892f2c 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.weak.modular.expect
index c4a01a2fd5fcc..51f0daf892f2c 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.weak.transformed.expect
index c4a01a2fd5fcc..51f0daf892f2c 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_parenthesized_pattern.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.strong.expect b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.strong.expect
index c4a01a2fd5fcc..7e3b7233fdd8d 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: var n?, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.strong.transformed.expect
index c4a01a2fd5fcc..7e3b7233fdd8d 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: var n?, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.weak.expect b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.weak.expect
index c4a01a2fd5fcc..7e3b7233fdd8d 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: var n?, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.weak.modular.expect
index c4a01a2fd5fcc..7e3b7233fdd8d 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: var n?, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.weak.transformed.expect
index c4a01a2fd5fcc..7e3b7233fdd8d 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_implicitly_named.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: var n?, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.strong.expect b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.strong.expect
index c4a01a2fd5fcc..3fd6ccf96bd36 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: 1?, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.strong.transformed.expect
index c4a01a2fd5fcc..3fd6ccf96bd36 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: 1?, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.weak.expect b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.weak.expect
index c4a01a2fd5fcc..3fd6ccf96bd36 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: 1?, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.weak.modular.expect
index c4a01a2fd5fcc..3fd6ccf96bd36 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: 1?, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.weak.transformed.expect
index c4a01a2fd5fcc..3fd6ccf96bd36 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_named.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: 1?, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.strong.expect b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.strong.expect
index c4a01a2fd5fcc..1e07a0c0b4062 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1?, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.strong.transformed.expect
index c4a01a2fd5fcc..1e07a0c0b4062 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1?, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.weak.expect b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.weak.expect
index c4a01a2fd5fcc..1e07a0c0b4062 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1?, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.weak.modular.expect
index c4a01a2fd5fcc..1e07a0c0b4062 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1?, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.weak.transformed.expect
index c4a01a2fd5fcc..1e07a0c0b4062 100644
--- a/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_check_inside_record_pattern_unnamed.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1?, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.strong.expect b/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.strong.expect
index c4a01a2fd5fcc..e1059d74ef672 100644
--- a/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case null as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.strong.transformed.expect
index c4a01a2fd5fcc..e1059d74ef672 100644
--- a/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case null as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.weak.expect b/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.weak.expect
index c4a01a2fd5fcc..e1059d74ef672 100644
--- a/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case null as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.weak.modular.expect
index c4a01a2fd5fcc..e1059d74ef672 100644
--- a/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case null as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.weak.transformed.expect
index c4a01a2fd5fcc..e1059d74ef672 100644
--- a/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_literal_inside_cast.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case null as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.strong.expect b/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.strong.expect
index c4a01a2fd5fcc..eb0fc5fa40329 100644
--- a/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case null!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.strong.transformed.expect
index c4a01a2fd5fcc..eb0fc5fa40329 100644
--- a/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case null!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.weak.expect b/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.weak.expect
index c4a01a2fd5fcc..eb0fc5fa40329 100644
--- a/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case null!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.weak.modular.expect
index c4a01a2fd5fcc..eb0fc5fa40329 100644
--- a/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case null!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.weak.transformed.expect
index c4a01a2fd5fcc..eb0fc5fa40329 100644
--- a/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_literal_inside_null_assert.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case null!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.strong.expect b/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.strong.expect
index c4a01a2fd5fcc..a630d7f7460c9 100644
--- a/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case null?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.strong.transformed.expect
index c4a01a2fd5fcc..a630d7f7460c9 100644
--- a/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case null?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.weak.expect b/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.weak.expect
index c4a01a2fd5fcc..a630d7f7460c9 100644
--- a/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case null?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.weak.modular.expect
index c4a01a2fd5fcc..a630d7f7460c9 100644
--- a/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case null?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.weak.transformed.expect
index c4a01a2fd5fcc..a630d7f7460c9 100644
--- a/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/null_literal_inside_null_check.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case null?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.strong.expect b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.strong.expect
index c4a01a2fd5fcc..96046d87ebf3f 100644
--- a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.strong.transformed.expect
index c4a01a2fd5fcc..96046d87ebf3f 100644
--- a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.weak.expect b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.weak.expect
index c4a01a2fd5fcc..96046d87ebf3f 100644
--- a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.weak.modular.expect
index c4a01a2fd5fcc..96046d87ebf3f 100644
--- a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.weak.transformed.expect
index c4a01a2fd5fcc..96046d87ebf3f 100644
--- a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_cast.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.strong.expect b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.strong.expect
index c4a01a2fd5fcc..08fa512a5011f 100644
--- a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.strong.transformed.expect
index c4a01a2fd5fcc..08fa512a5011f 100644
--- a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.weak.expect b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.weak.expect
index c4a01a2fd5fcc..08fa512a5011f 100644
--- a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.weak.modular.expect
index c4a01a2fd5fcc..08fa512a5011f 100644
--- a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.weak.transformed.expect
index c4a01a2fd5fcc..08fa512a5011f 100644
--- a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_assert.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.strong.expect b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.strong.expect
index c4a01a2fd5fcc..51f0daf892f2c 100644
--- a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.strong.transformed.expect
index c4a01a2fd5fcc..51f0daf892f2c 100644
--- a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.weak.expect b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.weak.expect
index c4a01a2fd5fcc..51f0daf892f2c 100644
--- a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.weak.modular.expect
index c4a01a2fd5fcc..51f0daf892f2c 100644
--- a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.weak.transformed.expect
index c4a01a2fd5fcc..51f0daf892f2c 100644
--- a/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/parenthesized_pattern_inside_null_check.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.strong.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.strong.expect
index 030449f744c60..f5119fd67c32a 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.strong.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.strong.transformed.expect
index 030449f744c60..f5119fd67c32a 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.strong.transformed.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.weak.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.weak.expect
index 030449f744c60..f5119fd67c32a 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.weak.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.weak.modular.expect
index 030449f744c60..f5119fd67c32a 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.weak.modular.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.weak.transformed.expect
index 030449f744c60..f5119fd67c32a 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args.dart.weak.transformed.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.strong.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.strong.expect
index 030449f744c60..ef323e3879563 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.strong.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern> as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.strong.transformed.expect
index 030449f744c60..ef323e3879563 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.strong.transformed.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern> as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.weak.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.weak.expect
index 030449f744c60..ef323e3879563 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.weak.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern> as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.weak.modular.expect
index 030449f744c60..ef323e3879563 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.weak.modular.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern> as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.weak.transformed.expect
index 030449f744c60..ef323e3879563 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_cast.dart.weak.transformed.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern> as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.strong.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.strong.expect
index 030449f744c60..cd2ac789d4356 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.strong.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.strong.transformed.expect
index 030449f744c60..cd2ac789d4356 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.strong.transformed.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.weak.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.weak.expect
index 030449f744c60..cd2ac789d4356 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.weak.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.weak.modular.expect
index 030449f744c60..cd2ac789d4356 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.weak.modular.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.weak.transformed.expect
index 030449f744c60..cd2ac789d4356 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_assert.dart.weak.transformed.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.strong.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.strong.expect
index 030449f744c60..a45a1c3b28501 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.strong.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.strong.transformed.expect
index 030449f744c60..a45a1c3b28501 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.strong.transformed.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.weak.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.weak.expect
index 030449f744c60..a45a1c3b28501 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.weak.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.weak.modular.expect
index 030449f744c60..a45a1c3b28501 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.weak.modular.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.weak.transformed.expect
index 030449f744c60..a45a1c3b28501 100644
--- a/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/prefixed_extractor_pattern_with_type_args_inside_null_check.dart.weak.transformed.expect
@@ -5,15 +5,8 @@ import "dart:async" as async;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.strong.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.strong.expect
index c4a01a2fd5fcc..081f1564b6b73 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.strong.transformed.expect
index c4a01a2fd5fcc..081f1564b6b73 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.weak.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.weak.expect
index c4a01a2fd5fcc..081f1564b6b73 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.weak.modular.expect
index c4a01a2fd5fcc..081f1564b6b73 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.weak.transformed.expect
index c4a01a2fd5fcc..081f1564b6b73 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_case.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.strong.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.strong.expect
index c4a01a2fd5fcc..14fd745318d65 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case ():
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.strong.transformed.expect
index c4a01a2fd5fcc..14fd745318d65 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case ():
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.weak.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.weak.expect
index c4a01a2fd5fcc..14fd745318d65 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case ():
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.weak.modular.expect
index c4a01a2fd5fcc..14fd745318d65 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case ():
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.weak.transformed.expect
index c4a01a2fd5fcc..14fd745318d65 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_case_empty.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case ():
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.strong.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.strong.expect
index c4a01a2fd5fcc..16530dbe3bd4d 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.strong.transformed.expect
index c4a01a2fd5fcc..16530dbe3bd4d 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.weak.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.weak.expect
index c4a01a2fd5fcc..16530dbe3bd4d 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.weak.modular.expect
index c4a01a2fd5fcc..16530dbe3bd4d 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.weak.transformed.expect
index c4a01a2fd5fcc..16530dbe3bd4d 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_case_singleton.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.strong.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.strong.expect
index c4a01a2fd5fcc..355e8bf53d1b8 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2) as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.strong.transformed.expect
index c4a01a2fd5fcc..355e8bf53d1b8 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2) as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.weak.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.weak.expect
index c4a01a2fd5fcc..355e8bf53d1b8 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2) as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.weak.modular.expect
index c4a01a2fd5fcc..355e8bf53d1b8 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2) as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.weak.transformed.expect
index c4a01a2fd5fcc..355e8bf53d1b8 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_cast.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2) as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.strong.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.strong.expect
index c4a01a2fd5fcc..c09f25149215a 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2)!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.strong.transformed.expect
index c4a01a2fd5fcc..c09f25149215a 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2)!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.weak.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.weak.expect
index c4a01a2fd5fcc..c09f25149215a 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2)!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.weak.modular.expect
index c4a01a2fd5fcc..c09f25149215a 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2)!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.weak.transformed.expect
index c4a01a2fd5fcc..c09f25149215a 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_null_assert.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2)!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.strong.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.strong.expect
index c4a01a2fd5fcc..1bda1782f11e7 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2)?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.strong.transformed.expect
index c4a01a2fd5fcc..1bda1782f11e7 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2)?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.weak.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.weak.expect
index c4a01a2fd5fcc..1bda1782f11e7 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2)?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.weak.modular.expect
index c4a01a2fd5fcc..1bda1782f11e7 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2)?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.weak.transformed.expect
index c4a01a2fd5fcc..1bda1782f11e7 100644
--- a/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/record_pattern_inside_null_check.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (1, 2)?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.strong.expect b/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.strong.expect
index c4a01a2fd5fcc..c154f632f8241 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.strong.transformed.expect
index c4a01a2fd5fcc..c154f632f8241 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.weak.expect b/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.weak.expect
index c4a01a2fd5fcc..c154f632f8241 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.weak.modular.expect
index c4a01a2fd5fcc..c154f632f8241 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.weak.transformed.expect
index c4a01a2fd5fcc..c154f632f8241 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_equal.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.strong.expect b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.strong.expect
index c4a01a2fd5fcc..7a4af20b28a74 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case > 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.strong.transformed.expect
index c4a01a2fd5fcc..7a4af20b28a74 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case > 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.weak.expect b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.weak.expect
index c4a01a2fd5fcc..7a4af20b28a74 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case > 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.weak.modular.expect
index c4a01a2fd5fcc..7a4af20b28a74 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case > 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.weak.transformed.expect
index c4a01a2fd5fcc..7a4af20b28a74 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case > 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.strong.expect b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.strong.expect
index c4a01a2fd5fcc..67b40f3f306ed 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case >= 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.strong.transformed.expect
index c4a01a2fd5fcc..67b40f3f306ed 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case >= 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.weak.expect b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.weak.expect
index c4a01a2fd5fcc..67b40f3f306ed 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case >= 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.weak.modular.expect
index c4a01a2fd5fcc..67b40f3f306ed 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case >= 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.weak.transformed.expect
index c4a01a2fd5fcc..67b40f3f306ed 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_greater_than_or_equal.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case >= 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.strong.expect b/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.strong.expect
index c4a01a2fd5fcc..67e07c6f94173 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case < 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.strong.transformed.expect
index c4a01a2fd5fcc..67e07c6f94173 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case < 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.weak.expect b/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.weak.expect
index c4a01a2fd5fcc..67e07c6f94173 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case < 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.weak.modular.expect
index c4a01a2fd5fcc..67e07c6f94173 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case < 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.weak.transformed.expect
index c4a01a2fd5fcc..67e07c6f94173 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_less_than.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case < 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.strong.expect b/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.strong.expect
index c4a01a2fd5fcc..7789cf47fca52 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <= 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.strong.transformed.expect
index c4a01a2fd5fcc..7789cf47fca52 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <= 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.weak.expect b/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.weak.expect
index c4a01a2fd5fcc..7789cf47fca52 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <= 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.weak.modular.expect
index c4a01a2fd5fcc..7789cf47fca52 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <= 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.weak.transformed.expect
index c4a01a2fd5fcc..7789cf47fca52 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_less_than_or_equal.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <= 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.strong.expect b/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.strong.expect
index c4a01a2fd5fcc..49038f8bd29d7 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case != 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.strong.transformed.expect
index c4a01a2fd5fcc..49038f8bd29d7 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case != 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.weak.expect b/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.weak.expect
index c4a01a2fd5fcc..49038f8bd29d7 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case != 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.weak.modular.expect
index c4a01a2fd5fcc..49038f8bd29d7 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case != 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.weak.transformed.expect
index c4a01a2fd5fcc..49038f8bd29d7 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_case_not_equal.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case != 1 << 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.strong.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.strong.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.strong.transformed.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.strong.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.weak.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.weak.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.weak.modular.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.weak.modular.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.weak.transformed.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_extractor_pattern.dart.weak.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.strong.expect
index c4a01a2fd5fcc..d330055e40da3 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[== 1]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.strong.transformed.expect
index c4a01a2fd5fcc..d330055e40da3 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[== 1]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.weak.expect
index c4a01a2fd5fcc..d330055e40da3 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[== 1]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.weak.modular.expect
index c4a01a2fd5fcc..d330055e40da3 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[== 1]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.weak.transformed.expect
index c4a01a2fd5fcc..d330055e40da3 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_list_pattern.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[== 1]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.strong.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.strong.expect
index c4a01a2fd5fcc..c1c15a6f70f40 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1 & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..c1c15a6f70f40 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1 & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.weak.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.weak.expect
index c4a01a2fd5fcc..c1c15a6f70f40 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1 & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.weak.modular.expect
index c4a01a2fd5fcc..c1c15a6f70f40 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1 & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..c1c15a6f70f40 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_and_lhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1 & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.strong.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.strong.expect
index c4a01a2fd5fcc..c72bd66cd3323 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & == 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..c72bd66cd3323 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & == 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.weak.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.weak.expect
index c4a01a2fd5fcc..c72bd66cd3323 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & == 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.weak.modular.expect
index c4a01a2fd5fcc..c72bd66cd3323 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & == 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..c72bd66cd3323 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_and_rhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & == 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.strong.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.strong.expect
index c4a01a2fd5fcc..c7eaac135b941 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1 | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..c7eaac135b941 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1 | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.weak.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.weak.expect
index c4a01a2fd5fcc..c7eaac135b941 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1 | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.weak.modular.expect
index c4a01a2fd5fcc..c7eaac135b941 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1 | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..c7eaac135b941 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_or_lhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1 | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.strong.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.strong.expect
index c4a01a2fd5fcc..d08bf65d46815 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | == 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..d08bf65d46815 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | == 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.weak.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.weak.expect
index c4a01a2fd5fcc..d08bf65d46815 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | == 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.weak.modular.expect
index c4a01a2fd5fcc..d08bf65d46815 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | == 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..d08bf65d46815 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_logical_or_rhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | == 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.strong.expect
index c4a01a2fd5fcc..bdff4f0111d27 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": == 1}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.strong.transformed.expect
index c4a01a2fd5fcc..bdff4f0111d27 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": == 1}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.weak.expect
index c4a01a2fd5fcc..bdff4f0111d27 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": == 1}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.weak.modular.expect
index c4a01a2fd5fcc..bdff4f0111d27 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": == 1}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.weak.transformed.expect
index c4a01a2fd5fcc..bdff4f0111d27 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_map_pattern.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": == 1}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.strong.expect
index c4a01a2fd5fcc..6edcdfa8441be 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.strong.transformed.expect
index c4a01a2fd5fcc..6edcdfa8441be 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.weak.expect
index c4a01a2fd5fcc..6edcdfa8441be 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.weak.modular.expect
index c4a01a2fd5fcc..6edcdfa8441be 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.weak.transformed.expect
index c4a01a2fd5fcc..6edcdfa8441be 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_parenthesized_pattern.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case == 1:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.strong.expect b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.strong.expect
index c4a01a2fd5fcc..e1c729453f0d9 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: == 1, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.strong.transformed.expect
index c4a01a2fd5fcc..e1c729453f0d9 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: == 1, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.weak.expect b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.weak.expect
index c4a01a2fd5fcc..e1c729453f0d9 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: == 1, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.weak.modular.expect
index c4a01a2fd5fcc..e1c729453f0d9 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: == 1, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.weak.transformed.expect
index c4a01a2fd5fcc..e1c729453f0d9 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_named.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: == 1, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.strong.expect b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.strong.expect
index c4a01a2fd5fcc..94b7a4606aac8 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (== 1, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.strong.transformed.expect
index c4a01a2fd5fcc..94b7a4606aac8 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (== 1, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.weak.expect b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.weak.expect
index c4a01a2fd5fcc..94b7a4606aac8 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (== 1, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.weak.modular.expect
index c4a01a2fd5fcc..94b7a4606aac8 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (== 1, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.weak.transformed.expect
index c4a01a2fd5fcc..94b7a4606aac8 100644
--- a/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/relational_inside_record_pattern_unnamed.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (== 1, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.strong.expect b/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.strong.expect
index c4a01a2fd5fcc..8077c4edf7af1 100644
--- a/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case \"x\" as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.strong.transformed.expect
index c4a01a2fd5fcc..8077c4edf7af1 100644
--- a/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case \"x\" as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.weak.expect b/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.weak.expect
index c4a01a2fd5fcc..8077c4edf7af1 100644
--- a/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case \"x\" as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.weak.modular.expect
index c4a01a2fd5fcc..8077c4edf7af1 100644
--- a/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case \"x\" as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.weak.transformed.expect
index c4a01a2fd5fcc..8077c4edf7af1 100644
--- a/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/string_literal_inside_cast.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case \"x\" as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.strong.expect b/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.strong.expect
index c4a01a2fd5fcc..0d1de115da3fd 100644
--- a/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case \"x\"!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.strong.transformed.expect
index c4a01a2fd5fcc..0d1de115da3fd 100644
--- a/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case \"x\"!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.weak.expect b/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.weak.expect
index c4a01a2fd5fcc..0d1de115da3fd 100644
--- a/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case \"x\"!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.weak.modular.expect
index c4a01a2fd5fcc..0d1de115da3fd 100644
--- a/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case \"x\"!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.weak.transformed.expect
index c4a01a2fd5fcc..0d1de115da3fd 100644
--- a/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/string_literal_inside_null_assert.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case \"x\"!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.strong.expect b/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.strong.expect
index c4a01a2fd5fcc..2d855ee396365 100644
--- a/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case \"x\"?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.strong.transformed.expect
index c4a01a2fd5fcc..2d855ee396365 100644
--- a/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case \"x\"?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.weak.expect b/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.weak.expect
index c4a01a2fd5fcc..2d855ee396365 100644
--- a/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case \"x\"?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.weak.modular.expect
index c4a01a2fd5fcc..2d855ee396365 100644
--- a/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case \"x\"?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.weak.transformed.expect
index c4a01a2fd5fcc..2d855ee396365 100644
--- a/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/string_literal_inside_null_check.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case \"x\"?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.strong.expect
index c4a01a2fd5fcc..b100a56968992 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.strong.transformed.expect
index c4a01a2fd5fcc..b100a56968992 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.weak.expect
index c4a01a2fd5fcc..b100a56968992 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.weak.modular.expect
index c4a01a2fd5fcc..b100a56968992 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.weak.transformed.expect
index c4a01a2fd5fcc..b100a56968992 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_case.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.strong.expect
index c4a01a2fd5fcc..769e07ed9c06a 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.strong.transformed.expect
index c4a01a2fd5fcc..769e07ed9c06a 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.weak.expect
index c4a01a2fd5fcc..769e07ed9c06a 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.weak.modular.expect
index c4a01a2fd5fcc..769e07ed9c06a 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.weak.transformed.expect
index c4a01a2fd5fcc..769e07ed9c06a 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_cast.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.strong.expect
index c4a01a2fd5fcc..69aeb67e3ebb3 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.strong.transformed.expect
index c4a01a2fd5fcc..69aeb67e3ebb3 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.weak.expect
index c4a01a2fd5fcc..69aeb67e3ebb3 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.weak.modular.expect
index c4a01a2fd5fcc..69aeb67e3ebb3 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.weak.transformed.expect
index c4a01a2fd5fcc..69aeb67e3ebb3 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_assert.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.strong.expect
index c4a01a2fd5fcc..d3a6b3d6dbc68 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.strong.transformed.expect
index c4a01a2fd5fcc..d3a6b3d6dbc68 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.weak.expect
index c4a01a2fd5fcc..d3a6b3d6dbc68 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.weak.modular.expect
index c4a01a2fd5fcc..d3a6b3d6dbc68 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.weak.transformed.expect
index c4a01a2fd5fcc..d3a6b3d6dbc68 100644
--- a/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_final_variable_inside_null_check.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.strong.expect
index c4a01a2fd5fcc..b100a56968992 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.strong.transformed.expect
index c4a01a2fd5fcc..b100a56968992 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.weak.expect
index c4a01a2fd5fcc..b100a56968992 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.weak.modular.expect
index c4a01a2fd5fcc..b100a56968992 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.weak.transformed.expect
index c4a01a2fd5fcc..b100a56968992 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_case.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.strong.expect
index c4a01a2fd5fcc..769e07ed9c06a 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.strong.transformed.expect
index c4a01a2fd5fcc..769e07ed9c06a 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.weak.expect
index c4a01a2fd5fcc..769e07ed9c06a 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.weak.modular.expect
index c4a01a2fd5fcc..769e07ed9c06a 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.weak.transformed.expect
index c4a01a2fd5fcc..769e07ed9c06a 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_cast.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.strong.expect
index c4a01a2fd5fcc..69aeb67e3ebb3 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.strong.transformed.expect
index c4a01a2fd5fcc..69aeb67e3ebb3 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.weak.expect
index c4a01a2fd5fcc..69aeb67e3ebb3 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.weak.modular.expect
index c4a01a2fd5fcc..69aeb67e3ebb3 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.weak.transformed.expect
index c4a01a2fd5fcc..69aeb67e3ebb3 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_null_assert.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.strong.expect
index c4a01a2fd5fcc..d3a6b3d6dbc68 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.strong.transformed.expect
index c4a01a2fd5fcc..d3a6b3d6dbc68 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.weak.expect
index c4a01a2fd5fcc..d3a6b3d6dbc68 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.weak.modular.expect
index c4a01a2fd5fcc..d3a6b3d6dbc68 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.weak.transformed.expect
index c4a01a2fd5fcc..d3a6b3d6dbc68 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_inside_null_check.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.strong.expect
index c4a01a2fd5fcc..89812f3fe5d0d 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.strong.transformed.expect
index c4a01a2fd5fcc..89812f3fe5d0d 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.weak.expect
index c4a01a2fd5fcc..89812f3fe5d0d 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.weak.modular.expect
index c4a01a2fd5fcc..89812f3fe5d0d 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.weak.transformed.expect
index c4a01a2fd5fcc..89812f3fe5d0d 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_case.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.strong.expect
index c4a01a2fd5fcc..1dbb3e3ffb402 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.strong.transformed.expect
index c4a01a2fd5fcc..1dbb3e3ffb402 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.weak.expect
index c4a01a2fd5fcc..1dbb3e3ffb402 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.weak.modular.expect
index c4a01a2fd5fcc..1dbb3e3ffb402 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.weak.transformed.expect
index c4a01a2fd5fcc..1dbb3e3ffb402 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_cast.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.strong.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.strong.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.strong.transformed.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.strong.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.weak.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.weak.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.weak.modular.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.weak.modular.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.weak.transformed.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern.dart.weak.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.strong.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.strong.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.strong.transformed.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.strong.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.weak.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.weak.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.weak.modular.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.weak.modular.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.weak.transformed.expect
index 9c70e8d02e902..4fe1dc45e24e0 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_extractor_pattern_implicitly_named.dart.weak.transformed.expect
@@ -10,15 +10,8 @@ class C extends core::Object {
 }
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <dummy-pattern>:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.strong.expect
index c4a01a2fd5fcc..25df676fe5ab4 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[int as]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.strong.transformed.expect
index c4a01a2fd5fcc..25df676fe5ab4 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[int as]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.weak.expect
index c4a01a2fd5fcc..25df676fe5ab4 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[int as]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.weak.modular.expect
index c4a01a2fd5fcc..25df676fe5ab4 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[int as]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.weak.transformed.expect
index c4a01a2fd5fcc..25df676fe5ab4 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_list_pattern.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case <<implicit-type-argument>>[int as]:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.strong.expect
index c4a01a2fd5fcc..9bc60d1f47372 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..9bc60d1f47372 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.weak.expect
index c4a01a2fd5fcc..9bc60d1f47372 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.weak.modular.expect
index c4a01a2fd5fcc..9bc60d1f47372 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..9bc60d1f47372 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_lhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as & 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.strong.expect
index c4a01a2fd5fcc..80567889c4781 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..80567889c4781 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.weak.expect
index c4a01a2fd5fcc..80567889c4781 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.weak.modular.expect
index c4a01a2fd5fcc..80567889c4781 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..80567889c4781 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_and_rhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 & int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.strong.expect
index c4a01a2fd5fcc..15f2d2910254f 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..15f2d2910254f 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.weak.expect
index c4a01a2fd5fcc..15f2d2910254f 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.weak.modular.expect
index c4a01a2fd5fcc..15f2d2910254f 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..15f2d2910254f 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_lhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as | 2:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.strong.expect
index c4a01a2fd5fcc..3960db67b113e 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.strong.transformed.expect
index c4a01a2fd5fcc..3960db67b113e 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.weak.expect
index c4a01a2fd5fcc..3960db67b113e 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.weak.modular.expect
index c4a01a2fd5fcc..3960db67b113e 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.weak.transformed.expect
index c4a01a2fd5fcc..3960db67b113e 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_logical_or_rhs.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case 1 | int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.strong.expect
index c4a01a2fd5fcc..ce8bb65bd5d57 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": int as}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.strong.transformed.expect
index c4a01a2fd5fcc..ce8bb65bd5d57 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": int as}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.weak.expect
index c4a01a2fd5fcc..ce8bb65bd5d57 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": int as}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.weak.modular.expect
index c4a01a2fd5fcc..ce8bb65bd5d57 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": int as}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.weak.transformed.expect
index c4a01a2fd5fcc..ce8bb65bd5d57 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_map_pattern.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case {\"a\": int as}:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.strong.expect
index c4a01a2fd5fcc..0d55f7513bb11 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.strong.transformed.expect
index c4a01a2fd5fcc..0d55f7513bb11 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.weak.expect
index c4a01a2fd5fcc..0d55f7513bb11 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.weak.modular.expect
index c4a01a2fd5fcc..0d55f7513bb11 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.weak.transformed.expect
index c4a01a2fd5fcc..0d55f7513bb11 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_assert.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.strong.expect
index c4a01a2fd5fcc..967286d96b51a 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.strong.transformed.expect
index c4a01a2fd5fcc..967286d96b51a 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.weak.expect
index c4a01a2fd5fcc..967286d96b51a 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.weak.modular.expect
index c4a01a2fd5fcc..967286d96b51a 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.weak.transformed.expect
index c4a01a2fd5fcc..967286d96b51a 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_null_check.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.strong.expect
index c4a01a2fd5fcc..89812f3fe5d0d 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.strong.transformed.expect
index c4a01a2fd5fcc..89812f3fe5d0d 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.weak.expect
index c4a01a2fd5fcc..89812f3fe5d0d 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.weak.modular.expect
index c4a01a2fd5fcc..89812f3fe5d0d 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.weak.transformed.expect
index c4a01a2fd5fcc..89812f3fe5d0d 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_parenthesized_pattern.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case int as:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.strong.expect
index c4a01a2fd5fcc..3d0628e41cb24 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: int as, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.strong.transformed.expect
index c4a01a2fd5fcc..3d0628e41cb24 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: int as, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.weak.expect
index c4a01a2fd5fcc..3d0628e41cb24 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: int as, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.weak.modular.expect
index c4a01a2fd5fcc..3d0628e41cb24 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: int as, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.weak.transformed.expect
index c4a01a2fd5fcc..3d0628e41cb24 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_implicitly_named.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (: int as, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.strong.expect
index c4a01a2fd5fcc..13ea3366fe81c 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: int as, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.strong.transformed.expect
index c4a01a2fd5fcc..13ea3366fe81c 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: int as, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.weak.expect
index c4a01a2fd5fcc..13ea3366fe81c 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: int as, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.weak.modular.expect
index c4a01a2fd5fcc..13ea3366fe81c 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: int as, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.weak.transformed.expect
index c4a01a2fd5fcc..13ea3366fe81c 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_named.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (n: int as, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.strong.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.strong.expect
index c4a01a2fd5fcc..dd6a001f90df6 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (int as, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.strong.transformed.expect
index c4a01a2fd5fcc..dd6a001f90df6 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (int as, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.weak.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.weak.expect
index c4a01a2fd5fcc..dd6a001f90df6 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (int as, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.weak.modular.expect
index c4a01a2fd5fcc..dd6a001f90df6 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (int as, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.weak.transformed.expect
index c4a01a2fd5fcc..dd6a001f90df6 100644
--- a/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/typed_variable_named_as_inside_record_pattern_unnamed.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case (int as, 2):
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.strong.expect b/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.strong.expect
index c4a01a2fd5fcc..2931fd83041f3 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.strong.transformed.expect
index c4a01a2fd5fcc..2931fd83041f3 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.weak.expect b/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.weak.expect
index c4a01a2fd5fcc..2931fd83041f3 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.weak.modular.expect
index c4a01a2fd5fcc..2931fd83041f3 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.weak.transformed.expect
index c4a01a2fd5fcc..2931fd83041f3 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_case.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.strong.expect b/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.strong.expect
index c4a01a2fd5fcc..3b256661485b3 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.strong.transformed.expect
index c4a01a2fd5fcc..3b256661485b3 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.weak.expect b/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.weak.expect
index c4a01a2fd5fcc..3b256661485b3 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.weak.modular.expect
index c4a01a2fd5fcc..3b256661485b3 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.weak.transformed.expect
index c4a01a2fd5fcc..3b256661485b3 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_cast.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y as Object:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.strong.expect b/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.strong.expect
index c4a01a2fd5fcc..0ef002717808b 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.strong.transformed.expect
index c4a01a2fd5fcc..0ef002717808b 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.weak.expect b/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.weak.expect
index c4a01a2fd5fcc..0ef002717808b 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.weak.modular.expect
index c4a01a2fd5fcc..0ef002717808b 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.weak.transformed.expect
index c4a01a2fd5fcc..0ef002717808b 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_null_assert.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y!:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.strong.expect b/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.strong.expect
index c4a01a2fd5fcc..dfe66ea1dc012 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.strong.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.strong.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.strong.transformed.expect b/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.strong.transformed.expect
index c4a01a2fd5fcc..dfe66ea1dc012 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.strong.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.weak.expect b/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.weak.expect
index c4a01a2fd5fcc..dfe66ea1dc012 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.weak.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.weak.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.weak.modular.expect b/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.weak.modular.expect
index c4a01a2fd5fcc..dfe66ea1dc012 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.weak.modular.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y?:
+    break label0;
+})";
 }
diff --git a/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.weak.transformed.expect b/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.weak.transformed.expect
index c4a01a2fd5fcc..dfe66ea1dc012 100644
--- a/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/patterns/var_variable_inside_null_check.dart.weak.transformed.expect
@@ -3,15 +3,8 @@ import self as self;
 
 static method test(dynamic x) → dynamic {
   #L1:
-  switch(x) {
-    #L2:
-    case #C1:
-      {
-        break #L1;
-      }
-  }
-}
-
-constants  {
-  #C1 = null
+  invalid-expression "PatternSwitchStatement(switch (x) {
+  case var y?:
+    break label0;
+})";
 }
diff --git a/tests/language/switch/case_expression_with_assignment_test.dart b/tests/language/switch/case_expression_with_assignment_test.dart
index 5ab2dbd89fb61..76a4d38f574de 100644
--- a/tests/language/switch/case_expression_with_assignment_test.dart
+++ b/tests/language/switch/case_expression_with_assignment_test.dart
@@ -18,8 +18,7 @@ errorToString(error) {
     // [analyzer] COMPILE_TIME_ERROR.ASSIGNMENT_TO_CONST
     //   ^^^^^^^^^^^
     // [analyzer] COMPILE_TIME_ERROR.NON_CONSTANT_CASE_EXPRESSION
-    //           ^
-    // [cfe] Not a constant expression.
+    // [cfe] Setter not found: 'ERROR_B'.
     case ERROR_B:
       return "ERROR_B";
     default:
diff --git a/tests/language_2/switch/case_expression_with_assignment_test.dart b/tests/language_2/switch/case_expression_with_assignment_test.dart
index 9ba6399401cbd..30c03646650dc 100644
--- a/tests/language_2/switch/case_expression_with_assignment_test.dart
+++ b/tests/language_2/switch/case_expression_with_assignment_test.dart
@@ -20,8 +20,7 @@ errorToString(error) {
     // [analyzer] COMPILE_TIME_ERROR.ASSIGNMENT_TO_CONST
     //   ^^^^^^^^^^^
     // [analyzer] COMPILE_TIME_ERROR.NON_CONSTANT_CASE_EXPRESSION
-    //           ^
-    // [cfe] Not a constant expression.
+    // [cfe] Setter not found: 'ERROR_B'.
     case ERROR_B:
       return "ERROR_B";
     default:
diff --git a/tools/VERSION b/tools/VERSION
index e834b0eaa8c90..faa85cd6688fc 100644
--- a/tools/VERSION
+++ b/tools/VERSION
@@ -27,5 +27,5 @@ CHANNEL dev
 MAJOR 2
 MINOR 19
 PATCH 0
-PRERELEASE 432
+PRERELEASE 433
 PRERELEASE_PATCH 0