[tests] Language tests for errors when implementing a 2.19 class that…

… implements a core library base or final class.

Bug: #52078
Change-Id: If97895b9560475f11e8236de87ad5880bdee97c3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/300880
Reviewed-by: Lasse Nielsen <[email protected]>
Commit-Queue: Kallen Tu <[email protected]>

tests/language/class_modifiers/base_transitivity/base_class_different_library_error_test.dart

@@ -6,7 +6,9 @@
 
 /// Test the invalid uses of a base class defined in a different library
 
+import 'dart:collection';
 import "shared_library_definitions.dart" show SimpleClass, BaseClass;
+import 'shared_library_definitions_legacy.dart' show LegacyImplementBaseCore;
 
 mixin _MixinOnObject {}
 
@@ -467,6 +469,14 @@ base mixin BaseMixinImplement implements BaseClass {}
 // [analyzer] COMPILE_TIME_ERROR.INVALID_USE_OF_TYPE_OUTSIDE_LIBRARY
 // [cfe] The class 'BaseClass' can't be implemented outside of its library because it's a base class.
 
+// Implementing a legacy class that implements a core library base class.
+
+abstract class LegacyImplement<E extends LinkedListEntry<E>>
+    implements LegacyImplementBaseCore<E> {}
+//             ^^^^^^^^^^^^^^^^^^^^^^^^^^
+// [analyzer] COMPILE_TIME_ERROR.INVALID_USE_OF_TYPE_OUTSIDE_LIBRARY
+// [cfe] unspecified
+
 /// It is an error if BaseClass is the `on` type of something which is not base.
 
 mixin SimpleMixinOn on BaseClass {}

tests/language/class_modifiers/base_transitivity/final_class_different_library_error_test.dart

@@ -7,6 +7,7 @@
 /// Test the invalid uses of a final class defined in a different library
 
 import "shared_library_definitions.dart" show FinalClass, SimpleClass;
+import 'shared_library_definitions_legacy.dart' show LegacyImplementFinalCore;
 
 mixin _MixinOnObject {}
 
@@ -184,6 +185,17 @@ base mixin BaseMixinImplement implements FinalClass {}
 // [analyzer] COMPILE_TIME_ERROR.INVALID_USE_OF_TYPE_OUTSIDE_LIBRARY
 // [cfe] The class 'FinalClass' can't be implemented outside of its library because it's a final class.
 
+// Implementing a legacy class that implements a core library final class.
+
+class LegacyImplement implements LegacyImplementFinalCore {
+//                               ^^^^^^^^^^^^^^^^^^^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+  int get key => 0;
+  int get value => 1;
+  String toString() => "Bad";
+}
+
 // It is an error if FinalClass is the `on` type of a mixin outside of
 // FinalClass' library.
 

tests/language/class_modifiers/base_transitivity/shared_library_definitions_legacy.dart

@@ -0,0 +1,21 @@
+// Copyright (c) 2023, 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.
+
+// SharedOptions=--enable-experiment=class-modifiers
+
+// @dart=2.19
+
+import 'dart:collection';
+
+/// Legacy library which defines some classes and mixins to be used to test
+/// behaviors across libraries.
+
+abstract class LegacyImplementBaseCore<E extends LinkedListEntry<E>>
+    implements LinkedList<E> {}
+
+class LegacyImplementFinalCore implements MapEntry<int, int> {
+  int get key => 0;
+  int get value => 1;
+  String toString() => "Bad";
+}