[wildcard-variables] Tests with this and super initializing formal pa…

…rameters.

Next set of tests with initializing formal parameters.

Bug: #55652
Change-Id: I1d8ff69249ad75c8065a159c333f91b62b30f769
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/367822
Commit-Queue: Kallen Tu <kallentu@google.com>
Reviewed-by: Lasse Nielsen <lrn@google.com>

tests/language/wildcard_variables/initializing_formal_parameters/super_test.dart

@@ -0,0 +1,45 @@
+// 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.
+
+// `super._` will pass on the given actual argument to the corresponding
+// superconstructor parameter.
+
+// SharedOptions=--enable-experiment=wildcard-variables
+
+import 'package:expect/expect.dart';
+
+void main() {
+  var c = C(1);
+  Expect.equals(1, c._);
+
+  var cWithPositional = C.withPositional(1, 100);
+  Expect.equals(1, cWithPositional._);
+
+  var multipleSuperParameters = MultipleSuperParameters(1, 2, 3);
+  Expect.equals(1, multipleSuperParameters._);
+  Expect.equals(2, multipleSuperParameters.x);
+  Expect.equals(3, multipleSuperParameters.y);
+}
+
+class B<_> {
+  var _;
+
+  B(this._);
+  B.withPositional(this._, _);
+}
+
+class C<_> extends B {
+  C(super._);
+  C.superAndPositional(super._, _);
+}
+
+class MultipleParameters {
+  final int x, y;
+  MultipleParameters(this.x, this.y);
+}
+
+class MultipleSuperParameters extends MultipleParameters {
+  final int _;
+  MultipleSuperParameters(this._, super._, super._);
+}

tests/language/wildcard_variables/initializing_formal_parameters/this_initializer_access_error_test.dart

@@ -0,0 +1,27 @@
+// 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.
+
+// It's an error for `_` to be accessed inside an initializer list.
+
+// SharedOptions=--enable-experiment=wildcard-variables
+
+class C {
+  var _;
+  var other;
+
+  C(this._) : other = _;
+//^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+class CWithTypeParameter<_> {
+  var _;
+  var other;
+
+  CWithTypeParameter(this._) : other = _;
+//^
+// [analyzer] unspecified
+// [cfe] unspecified
+}

tests/language/wildcard_variables/initializing_formal_parameters/this_initializer_multiple_error_test.dart

@@ -0,0 +1,21 @@
+// 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.
+
+// It's an error to have two initializing formals named `_`.
+
+// SharedOptions=--enable-experiment=wildcard-variables
+
+class C {
+  var _;
+
+  C(this._, this._);
+//^
+// [analyzer] unspecified
+// [cfe] unspecified
+
+  C.named(this._, this._);
+//^
+// [analyzer] unspecified
+// [cfe] unspecified
+}

tests/language/wildcard_variables/initializing_formal_parameters/this_test.dart

@@ -0,0 +1,31 @@
+// 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.
+
+// A positional initializing formal named `_` does still initialize a field
+// named `_`, and you can still have a field with that name.
+
+// SharedOptions=--enable-experiment=wildcard-variables
+
+import 'package:expect/expect.dart';
+
+void main() {
+  var c = C(1);
+  Expect.equals(1, c._);
+
+  var cWithPositional = C.withPositional(1, 100);
+  Expect.equals(1, cWithPositional._);
+
+  var cWithBody = C.withBody(1);
+  Expect.equals(200, cWithBody._);
+}
+
+class C<_> {
+  var _;
+
+  C(this._);
+  C.withPositional(this._, _);
+  C.withBody(this._) {
+    _ = 200;
+  }
+}