[cfe] Add ExtensionTypeRepresentationFieldInitializer.replaceChild

The added method is required for the resolution of redirection targets
to work: it replaces the immediate target invocation node with the
final target invocation node.

Closes #55135

Change-Id: I421f182192aae17f4bd3dcfe6d8216befde0e93e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/357161
Reviewed-by: Johnni Winther <[email protected]>
Commit-Queue: Chloe Stefantsova <[email protected]>

pkg/front_end/lib/src/fasta/kernel/internal_ast.dart

@@ -350,11 +350,6 @@ abstract class InternalExpression extends AuxiliaryExpression {
 
 /// Common base class for internal initializers.
 abstract class InternalInitializer extends AuxiliaryInitializer {
-  @override
-  void replaceChild(TreeNode child, TreeNode replacement) {
-    // Do nothing. The node should not be part of the resulting AST, anyway.
-  }
-
   @override
   void visitChildren(Visitor<dynamic> v) =>
       unsupported("${runtimeType}.visitChildren", -1, null);
@@ -3374,6 +3369,11 @@ class ExtensionTypeRepresentationFieldInitializer extends InternalInitializer {
     value.parent = this;
   }
 
+  @override
+  void transformChildren(Transformer v) {
+    value = v.transform(value)..parent = this;
+  }
+
   /// [Procedure] that represents the representation field.
   Procedure get field => fieldReference.asProcedure;
 

pkg/front_end/testcases/dart2js/issue55135.dart

@@ -0,0 +1,26 @@
+// Copyright (c) 2024, 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.
+
+class B implements A {
+  final int x = 1;
+}
+abstract class A {
+  int get x;
+  factory A() = B;
+}
+
+extension type C._(A point) implements A {
+  C() : point = A(); // << initializer is redirecting factory
+}
+
+void main() {
+  expectEquals(A().x, 1);
+  expectEquals(C().x, 1);
+}
+
+expectEquals(x, y) {
+  if (x != y) {
+    throw "Expected equal values, got '${x}' and '${y}'.";
+  }
+}

pkg/front_end/testcases/dart2js/issue55135.dart.strong.expect

@@ -0,0 +1,47 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+class B extends core::Object implements self::A {
+  final field core::int x = 1;
+  synthetic constructor •() → self::B
+    : super core::Object::•()
+    ;
+  static method _#new#tearOff() → self::B
+    return new self::B::•();
+}
+abstract class A extends core::Object {
+  abstract get x() → core::int;
+  static factory •() → self::A /* redirection-target: self::B::• */
+    return new self::B::•();
+  static method _#new#tearOff() → self::A
+    return new self::B::•();
+}
+extension type C(self::A point) implements self::A {
+  abstract extension-type-member representation-field get point() → self::A;
+  constructor _ = self::C|constructor#_;
+  constructor tearoff _ = self::C|constructor#_#_#tearOff;
+  constructor • = self::C|constructor#;
+  constructor tearoff • = self::C|constructor#_#new#tearOff;
+}
+static extension-type-member method C|constructor#_(self::A point) → self::C /* erasure=self::A */ {
+  lowered final self::C /* erasure=self::A */ #this = point;
+  return #this;
+}
+static extension-type-member method C|constructor#_#_#tearOff(self::A point) → self::C /* erasure=self::A */
+  return self::C|constructor#_(point);
+static extension-type-member method C|constructor#() → self::C /* erasure=self::A */ {
+  lowered final self::C /* erasure=self::A */ #this = new self::B::•();
+  return #this;
+}
+static extension-type-member method C|constructor#_#new#tearOff() → self::C /* erasure=self::A */
+  return self::C|constructor#();
+static method main() → void {
+  self::expectEquals(new self::B::•().{self::A::x}{core::int}, 1);
+  self::expectEquals(self::C|constructor#().{self::A::x}{core::int}, 1);
+}
+static method expectEquals(dynamic x, dynamic y) → dynamic {
+  if(!(x =={core::Object::==}{(core::Object) → core::bool} y)) {
+    throw "Expected equal values, got '${x}' and '${y}'.";
+  }
+}

pkg/front_end/testcases/dart2js/issue55135.dart.strong.transformed.expect

@@ -0,0 +1,47 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+class B extends core::Object implements self::A {
+  final field core::int x = 1;
+  synthetic constructor •() → self::B
+    : super core::Object::•()
+    ;
+  static method _#new#tearOff() → self::B
+    return new self::B::•();
+}
+abstract class A extends core::Object {
+  abstract get x() → core::int;
+  static factory •() → self::A /* redirection-target: self::B::• */
+    return new self::B::•();
+  static method _#new#tearOff() → self::A
+    return new self::B::•();
+}
+extension type C(self::A point) implements self::A {
+  abstract extension-type-member representation-field get point() → self::A;
+  constructor _ = self::C|constructor#_;
+  constructor tearoff _ = self::C|constructor#_#_#tearOff;
+  constructor • = self::C|constructor#;
+  constructor tearoff • = self::C|constructor#_#new#tearOff;
+}
+static extension-type-member method C|constructor#_(self::A point) → self::C /* erasure=self::A */ {
+  lowered final self::C /* erasure=self::A */ #this = point;
+  return #this;
+}
+static extension-type-member method C|constructor#_#_#tearOff(self::A point) → self::C /* erasure=self::A */
+  return self::C|constructor#_(point);
+static extension-type-member method C|constructor#() → self::C /* erasure=self::A */ {
+  lowered final self::C /* erasure=self::A */ #this = new self::B::•();
+  return #this;
+}
+static extension-type-member method C|constructor#_#new#tearOff() → self::C /* erasure=self::A */
+  return self::C|constructor#();
+static method main() → void {
+  self::expectEquals(new self::B::•().{self::A::x}{core::int}, 1);
+  self::expectEquals(self::C|constructor#().{self::A::x}{core::int}, 1);
+}
+static method expectEquals(dynamic x, dynamic y) → dynamic {
+  if(!(x =={core::Object::==}{(core::Object) → core::bool} y)) {
+    throw "Expected equal values, got '${x}' and '${y}'.";
+  }
+}

pkg/front_end/testcases/dart2js/issue55135.dart.textual_outline.expect

@@ -0,0 +1,16 @@
+class B implements A {
+  final int x = 1;
+}
+
+abstract class A {
+  int get x;
+  factory A() = B;
+}
+
+extension type C._(A point) implements A {
+  C() : point = A();
+}
+
+void main() {}
+
+expectEquals(x, y) {}

pkg/front_end/testcases/dart2js/issue55135.dart.textual_outline_modelled.expect

@@ -0,0 +1,16 @@
+abstract class A {
+  factory A() = B;
+  int get x;
+}
+
+class B implements A {
+  final int x = 1;
+}
+
+expectEquals(x, y) {}
+
+extension type C._(A point) implements A {
+  C() : point = A();
+}
+
+void main() {}

pkg/front_end/testcases/dart2js/issue55135.dart.weak.expect

@@ -0,0 +1,47 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+class B extends core::Object implements self::A {
+  final field core::int x = 1;
+  synthetic constructor •() → self::B
+    : super core::Object::•()
+    ;
+  static method _#new#tearOff() → self::B
+    return new self::B::•();
+}
+abstract class A extends core::Object {
+  abstract get x() → core::int;
+  static factory •() → self::A /* redirection-target: self::B::• */
+    return new self::B::•();
+  static method _#new#tearOff() → self::A
+    return new self::B::•();
+}
+extension type C(self::A point) implements self::A {
+  abstract extension-type-member representation-field get point() → self::A;
+  constructor _ = self::C|constructor#_;
+  constructor tearoff _ = self::C|constructor#_#_#tearOff;
+  constructor • = self::C|constructor#;
+  constructor tearoff • = self::C|constructor#_#new#tearOff;
+}
+static extension-type-member method C|constructor#_(self::A point) → self::C /* erasure=self::A */ {
+  lowered final self::C /* erasure=self::A */ #this = point;
+  return #this;
+}
+static extension-type-member method C|constructor#_#_#tearOff(self::A point) → self::C /* erasure=self::A */
+  return self::C|constructor#_(point);
+static extension-type-member method C|constructor#() → self::C /* erasure=self::A */ {
+  lowered final self::C /* erasure=self::A */ #this = new self::B::•();
+  return #this;
+}
+static extension-type-member method C|constructor#_#new#tearOff() → self::C /* erasure=self::A */
+  return self::C|constructor#();
+static method main() → void {
+  self::expectEquals(new self::B::•().{self::A::x}{core::int}, 1);
+  self::expectEquals(self::C|constructor#().{self::A::x}{core::int}, 1);
+}
+static method expectEquals(dynamic x, dynamic y) → dynamic {
+  if(!(x =={core::Object::==}{(core::Object) → core::bool} y)) {
+    throw "Expected equal values, got '${x}' and '${y}'.";
+  }
+}

pkg/front_end/testcases/dart2js/issue55135.dart.weak.modular.expect

@@ -0,0 +1,47 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+class B extends core::Object implements self::A {
+  final field core::int x = 1;
+  synthetic constructor •() → self::B
+    : super core::Object::•()
+    ;
+  static method _#new#tearOff() → self::B
+    return new self::B::•();
+}
+abstract class A extends core::Object {
+  abstract get x() → core::int;
+  static factory •() → self::A /* redirection-target: self::B::• */
+    return new self::B::•();
+  static method _#new#tearOff() → self::A
+    return new self::B::•();
+}
+extension type C(self::A point) implements self::A {
+  abstract extension-type-member representation-field get point() → self::A;
+  constructor _ = self::C|constructor#_;
+  constructor tearoff _ = self::C|constructor#_#_#tearOff;
+  constructor • = self::C|constructor#;
+  constructor tearoff • = self::C|constructor#_#new#tearOff;
+}
+static extension-type-member method C|constructor#_(self::A point) → self::C /* erasure=self::A */ {
+  lowered final self::C /* erasure=self::A */ #this = point;
+  return #this;
+}
+static extension-type-member method C|constructor#_#_#tearOff(self::A point) → self::C /* erasure=self::A */
+  return self::C|constructor#_(point);
+static extension-type-member method C|constructor#() → self::C /* erasure=self::A */ {
+  lowered final self::C /* erasure=self::A */ #this = new self::B::•();
+  return #this;
+}
+static extension-type-member method C|constructor#_#new#tearOff() → self::C /* erasure=self::A */
+  return self::C|constructor#();
+static method main() → void {
+  self::expectEquals(new self::B::•().{self::A::x}{core::int}, 1);
+  self::expectEquals(self::C|constructor#().{self::A::x}{core::int}, 1);
+}
+static method expectEquals(dynamic x, dynamic y) → dynamic {
+  if(!(x =={core::Object::==}{(core::Object) → core::bool} y)) {
+    throw "Expected equal values, got '${x}' and '${y}'.";
+  }
+}

pkg/front_end/testcases/dart2js/issue55135.dart.weak.outline.expect

@@ -0,0 +1,37 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+class B extends core::Object implements self::A {
+  final field core::int x;
+  synthetic constructor •() → self::B
+    ;
+  static method _#new#tearOff() → self::B
+    return new self::B::•();
+}
+abstract class A extends core::Object {
+  abstract get x() → core::int;
+  static factory •() → self::A /* redirection-target: self::B::• */
+    return new self::B::•();
+  static method _#new#tearOff() → self::A
+    return new self::B::•();
+}
+extension type C(self::A point) implements self::A {
+  abstract extension-type-member representation-field get point() → self::A;
+  constructor _ = self::C|constructor#_;
+  constructor tearoff _ = self::C|constructor#_#_#tearOff;
+  constructor • = self::C|constructor#;
+  constructor tearoff • = self::C|constructor#_#new#tearOff;
+}
+static extension-type-member method C|constructor#_(self::A point) → self::C /* erasure=self::A */
+  ;
+static extension-type-member method C|constructor#_#_#tearOff(self::A point) → self::C /* erasure=self::A */
+  return self::C|constructor#_(point);
+static extension-type-member method C|constructor#() → self::C /* erasure=self::A */
+  ;
+static extension-type-member method C|constructor#_#new#tearOff() → self::C /* erasure=self::A */
+  return self::C|constructor#();
+static method main() → void
+  ;
+static method expectEquals(dynamic x, dynamic y) → dynamic
+  ;

pkg/front_end/testcases/dart2js/issue55135.dart.weak.transformed.expect

@@ -0,0 +1,47 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+class B extends core::Object implements self::A {
+  final field core::int x = 1;
+  synthetic constructor •() → self::B
+    : super core::Object::•()
+    ;
+  static method _#new#tearOff() → self::B
+    return new self::B::•();
+}
+abstract class A extends core::Object {
+  abstract get x() → core::int;
+  static factory •() → self::A /* redirection-target: self::B::• */
+    return new self::B::•();
+  static method _#new#tearOff() → self::A
+    return new self::B::•();
+}
+extension type C(self::A point) implements self::A {
+  abstract extension-type-member representation-field get point() → self::A;
+  constructor _ = self::C|constructor#_;
+  constructor tearoff _ = self::C|constructor#_#_#tearOff;
+  constructor • = self::C|constructor#;
+  constructor tearoff • = self::C|constructor#_#new#tearOff;
+}
+static extension-type-member method C|constructor#_(self::A point) → self::C /* erasure=self::A */ {
+  lowered final self::C /* erasure=self::A */ #this = point;
+  return #this;
+}
+static extension-type-member method C|constructor#_#_#tearOff(self::A point) → self::C /* erasure=self::A */
+  return self::C|constructor#_(point);
+static extension-type-member method C|constructor#() → self::C /* erasure=self::A */ {
+  lowered final self::C /* erasure=self::A */ #this = new self::B::•();
+  return #this;
+}
+static extension-type-member method C|constructor#_#new#tearOff() → self::C /* erasure=self::A */
+  return self::C|constructor#();
+static method main() → void {
+  self::expectEquals(new self::B::•().{self::A::x}{core::int}, 1);
+  self::expectEquals(self::C|constructor#().{self::A::x}{core::int}, 1);
+}
+static method expectEquals(dynamic x, dynamic y) → dynamic {
+  if(!(x =={core::Object::==}{(core::Object) → core::bool} y)) {
+    throw "Expected equal values, got '${x}' and '${y}'.";
+  }
+}

pkg/front_end/testcases/extension_types/issue55135.dart

@@ -0,0 +1,26 @@
+// Copyright (c) 2024, 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.
+
+class B implements A {
+  final int x = 1;
+}
+abstract class A {
+  int get x;
+  factory A() = B;
+}
+
+extension type C._(A point) implements A {
+  C() : point = A(); // << initializer is redirecting factory
+}
+
+void main() {
+  expectEquals(A().x, 1);
+  expectEquals(C().x, 1);
+}
+
+expectEquals(x, y) {
+  if (x != y) {
+    throw "Expected equal values, got '${x}' and '${y}'.";
+  }
+}