LibTest/js_interop/anonymous_A03_t04.dart

// Copyright (c) 2025, 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 An annotation that indicates a JS annotated class is structural
/// and does not have a known JavaScript prototype.
///
/// A class marked with [anonymous] allows external factories with named
/// parameters. Invoking these factories creates a JavaScript object literal
/// with name-value pairs corresponding to any named parameters and their
/// values. If there are no named parameters, an empty JavaScript object is
/// created.
/// [anonymous] classes have the following restrictions:
///   - They must contain a [JS] annotation, either from this library or from
///     `dart:js_interop`. If the latter, the class must also contain
///     [staticInterop].
///   - They cannot contain any non-external members unless it's a
///     [staticInterop] class, in which case it can also contain non-external
///     factories and static methods.
///   - They cannot contain any external generative constructors.
///   - Any external factory must not contain any positional parameters.
///   - They cannot extend or be extended by a non-[JS] annotated class.
///   - The annotation should only be applied to non-mixin classes and no other
///     declarations.
///
/// @description Checks that it is a compile-time error if an extension
/// is annotated with `@anonymous`.
/// @author sgrekhov22@gmail.com
/// @issue 61082

import 'dart:js_interop';

class C1 {
  C1.n({String id = ""});
  factory C1({String id}) = C1.n;
}

@anonymous
@JS()
extension Ext1 on C1 {
//        ^^^^
// [analyzer] unspecified
// [web] unspecified
}

@anonymous
@staticInterop
@JS()
class C2 {
  external factory C2({String id});
}

@anonymous
extension Ext2 on C2 {
//        ^^^^
// [analyzer] unspecified
// [web] unspecified
}

main() {
   print(C1);
   print(C2);
}