Fixes #2436. Add tests for external and redirecting constructors with…

… initializing formals (#2460)

Language/Classes/Constructors/Generative_Constructors/initializing_formal_parameter_A01_t01.dart

@@ -0,0 +1,36 @@
+// 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.
+
+/// @assertion It is a compile-time error for an initializing formal parameter
+/// to occur in a redirecting or external constructor.
+///
+/// @description Checks that it is a compile-time error when the initializing
+/// formal parameter occurs in a redirecting constructor.
+/// @author [email protected]
+
+class C {
+  int? x;
+
+  C(this.x);
+  C.n(this.x) : this(0);
+//    ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+enum E {
+  a(1);
+
+  final int x;
+  const E(this.x);
+  const E.n(this.x) : this(1);
+//          ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+main() {
+  print(C);
+  print(E);
+}

Language/Classes/Constructors/Generative_Constructors/initializing_formal_parameter_A01_t02.dart

@@ -0,0 +1,36 @@
+// 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.
+
+/// @assertion It is a compile-time error for an initializing formal parameter
+/// to occur in a redirecting or external constructor.
+///
+/// @description Checks that it is a compile-time error when the initializing
+/// formal parameter occurs in a redirecting constructor.
+/// @author [email protected]
+
+class C {
+  int x;
+
+  C({this.x = 0});
+  C.n({this.x = 1}) : this(x: 0);
+//     ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+enum E {
+  a(x: 1);
+
+  final int x;
+  const E({this.x = 0});
+  const E.n({this.x = 2}) : this(x: 1);
+//           ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+main() {
+  print(C);
+  print(E);
+}

Language/Classes/Constructors/Generative_Constructors/initializing_formal_parameter_A01_t03.dart

@@ -0,0 +1,36 @@
+// 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.
+
+/// @assertion It is a compile-time error for an initializing formal parameter
+/// to occur in a redirecting or external constructor.
+///
+/// @description Checks that it is a compile-time error when the initializing
+/// formal parameter occurs in a redirecting constructor.
+/// @author [email protected]
+
+class C {
+  int x;
+
+  C({required this.x});
+  C.n({required this.x}) : this(x: 0);
+//     ^^^^^^^^^^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+enum E {
+  a(x: 1);
+
+  final int x;
+  const E({required this.x});
+  const E.n({required this.x}) : this(x: 1);
+//           ^^^^^^^^^^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+main() {
+  print(C);
+  print(E);
+}

Language/Classes/Constructors/Generative_Constructors/initializing_formal_parameter_A01_t04.dart

@@ -0,0 +1,36 @@
+// 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.
+
+/// @assertion It is a compile-time error for an initializing formal parameter
+/// to occur in a redirecting or external constructor.
+///
+/// @description Checks that it is a compile-time error when the initializing
+/// formal parameter occurs in a redirecting constructor.
+/// @author [email protected]
+
+class C {
+  int x;
+
+  C([this.x = 0]);
+  C.n([this.x = 1]) : this(0);
+//     ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+enum E {
+  a(1);
+
+  final int x;
+  const E([this.x = 0]);
+  const E.n([this.x = 2]) : this(1);
+//           ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+main() {
+  print(C);
+  print(E);
+}

Language/Classes/Constructors/Generative_Constructors/initializing_formal_parameter_A02_t01.dart

@@ -0,0 +1,35 @@
+// 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.
+
+/// @assertion It is a compile-time error for an initializing formal parameter
+/// to occur in a redirecting or external constructor.
+///
+/// @description Checks that it is a compile-time error when the initializing
+/// formal parameter occurs in an external constructor.
+/// @author [email protected]
+/// @issue 54485
+
+class C {
+  int? x;
+
+  external C(this.x);
+//           ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+enum E {
+  a(1);
+
+  final int x;
+  external const E(this.x);
+//                 ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+main() {
+  print(C);
+  print(E);
+}

Language/Classes/Constructors/Generative_Constructors/initializing_formal_parameter_A02_t02.dart

@@ -0,0 +1,35 @@
+// 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.
+
+/// @assertion It is a compile-time error for an initializing formal parameter
+/// to occur in a redirecting or external constructor.
+///
+/// @description Checks that it is a compile-time error when the initializing
+/// formal parameter occurs in an external constructor.
+/// @author [email protected]
+/// @issue 54485
+
+class C {
+  int x;
+
+  external C({this.x = 0});
+//            ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+enum E {
+  a(x: 1);
+
+  final int x;
+  external const E({this.x = 0});
+//                  ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+main() {
+  print(C);
+  print(E);
+}

Language/Classes/Constructors/Generative_Constructors/initializing_formal_parameter_A02_t03.dart

@@ -0,0 +1,35 @@
+// 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.
+
+/// @assertion It is a compile-time error for an initializing formal parameter
+/// to occur in a redirecting or external constructor.
+///
+/// @description Checks that it is a compile-time error when the initializing
+/// formal parameter occurs in an external constructor.
+/// @author [email protected]
+/// @issue 54485
+
+class C {
+  int x;
+
+  external C({required this.x});
+//            ^^^^^^^^^^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+enum E {
+  a(x: 1);
+
+  final int x;
+  external const E({required this.x});
+//                  ^^^^^^^^^^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+main() {
+  print(C);
+  print(E);
+}

Language/Classes/Constructors/Generative_Constructors/initializing_formal_parameter_A02_t04.dart

@@ -0,0 +1,35 @@
+// 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.
+
+/// @assertion It is a compile-time error for an initializing formal parameter
+/// to occur in a redirecting or external constructor.
+///
+/// @description Checks that it is a compile-time error when the initializing
+/// formal parameter occurs in an external constructor.
+/// @author [email protected]
+/// @issue 54485
+
+class C {
+  int x;
+
+  external C([this.x = 0]);
+//            ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+enum E {
+  a(1);
+
+  final int x;
+  external const E([this.x = 0]);
+//                  ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+main() {
+  print(C);
+  print(E);
+}