#3180. Add more tests for @anonymous annotation

LibTest/js_interop/anonymous_A01_t01.dart

@@ -5,10 +5,23 @@
 /// @assertion An annotation that indicates a JS annotated class is structural
 /// and does not have a known JavaScript prototype.
 ///
-/// A class marked with [anonymous] must have an unnamed factory constructor
-/// with no positional arguments, only named arguments. Invoking the constructor
-/// desugars to creating a JavaScript object literal with name-value pairs
-/// corresponding to the parameter names and values.
+/// 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 invoking the constructor desugars to creating a
 /// JavaScript object literal with name-value pairs corresponding to the

LibTest/js_interop/anonymous_A01_t02.dart

@@ -5,10 +5,23 @@
 /// @assertion An annotation that indicates a JS annotated class is structural
 /// and does not have a known JavaScript prototype.
 ///
-/// A class marked with [anonymous] must have an unnamed factory constructor
-/// with no positional arguments, only named arguments. Invoking the constructor
-/// desugars to creating a JavaScript object literal with name-value pairs
-/// corresponding to the parameter names and values.
+/// 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 invoking the constructor desugars to creating a
 /// JavaScript object literal with name-value pairs corresponding to the

LibTest/js_interop/anonymous_A02_t01.dart

@@ -5,10 +5,23 @@
 /// @assertion An annotation that indicates a JS annotated class is structural
 /// and does not have a known JavaScript prototype.
 ///
-/// A class marked with [anonymous] must have an unnamed factory constructor
-/// with no positional arguments, only named arguments. Invoking the constructor
-/// desugars to creating a JavaScript object literal with name-value pairs
-/// corresponding to the parameter names and values.
+/// 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 not an error if a class annotated with
 /// [anonymous] has no unnamed factory constructor. Creating an instance creates

LibTest/js_interop/anonymous_A03_t01.dart

@@ -5,10 +5,23 @@
 /// @assertion An annotation that indicates a JS annotated class is structural
 /// and does not have a known JavaScript prototype.
 ///
-/// A class marked with [anonymous] must have an unnamed factory constructor
-/// with no positional arguments, only named arguments. Invoking the constructor
-/// desugars to creating a JavaScript object literal with name-value pairs
-/// corresponding to the parameter names and values.
+/// 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 warning if an extension type is annotated
 /// with [anonymous].

LibTest/js_interop/anonymous_A03_t02.dart

@@ -5,10 +5,23 @@
 /// @assertion An annotation that indicates a JS annotated class is structural
 /// and does not have a known JavaScript prototype.
 ///
-/// A class marked with [anonymous] must have an unnamed factory constructor
-/// with no positional arguments, only named arguments. Invoking the constructor
-/// desugars to creating a JavaScript object literal with name-value pairs
-/// corresponding to the parameter names and values.
+/// 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 enum is annotated
 /// with [anonymous].

LibTest/js_interop/anonymous_A03_t03.dart

@@ -5,10 +5,23 @@
 /// @assertion An annotation that indicates a JS annotated class is structural
 /// and does not have a known JavaScript prototype.
 ///
-/// A class marked with [anonymous] must have an unnamed factory constructor
-/// with no positional arguments, only named arguments. Invoking the constructor
-/// desugars to creating a JavaScript object literal with name-value pairs
-/// corresponding to the parameter names and values.
+/// 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 a mixin is annotated
 /// with [anonymous].

LibTest/js_interop/anonymous_A03_t04.dart

@@ -5,10 +5,23 @@
 /// @assertion An annotation that indicates a JS annotated class is structural
 /// and does not have a known JavaScript prototype.
 ///
-/// A class marked with [anonymous] must have an unnamed factory constructor
-/// with no positional arguments, only named arguments. Invoking the constructor
-/// desugars to creating a JavaScript object literal with name-value pairs
-/// corresponding to the parameter names and values.
+/// 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`.

LibTest/js_interop/anonymous_A03_t05.dart

@@ -5,10 +5,23 @@
 /// @assertion An annotation that indicates a JS annotated class is structural
 /// and does not have a known JavaScript prototype.
 ///
-/// A class marked with [anonymous] must have an unnamed factory constructor
-/// with no positional arguments, only named arguments. Invoking the constructor
-/// desugars to creating a JavaScript object literal with name-value pairs
-/// corresponding to the parameter names and values.
+/// 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 a non-type is marked
 /// with [anonymous].

LibTest/js_interop/anonymous_A04_t01.dart

@@ -0,0 +1,56 @@
+// 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 external factory
+/// constructor of a class annotated with [anonymous] contains any positional
+/// parameters.
+/// @author sgrekhov22@gmail.com
+
+import 'dart:js_interop';
+
+@anonymous
+@staticInterop
+@JS()
+class C1 {
+  external factory C1(String s0, {String s, int n, bool b});
+//                           ^^
+// [analyzer] unspecified
+// [web] unspecified
+}
+
+@anonymous
+@staticInterop
+@JS()
+class C2 {
+  external factory C2.f(int n);
+//                          ^
+// [analyzer] unspecified
+// [web] unspecified
+}
+
+main() {
+  print(C1);
+  print(C2);
+}

LibTest/js_interop/anonymous_A05_t01.dart

@@ -0,0 +1,66 @@
+// 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 a class annotated
+/// with [anonymous] contains any generative constructors.
+/// @author sgrekhov22@gmail.com
+
+import 'dart:js_interop';
+
+@anonymous
+@staticInterop
+@JS()
+class C1 {
+  external C1({String s, int n, bool b});
+//         ^^
+// [analyzer] unspecified
+// [web] unspecified
+}
+
+@anonymous
+@staticInterop
+@JS()
+class C2 {
+  C2.f({String s = "", int n = 0, bool b = false});
+//^^^^
+// [analyzer] unspecified
+// [web] unspecified
+}
+
+@anonymous
+@staticInterop
+@JS()
+class C3 {
+  C3({required String s});
+//^^
+// [analyzer] unspecified
+// [web] unspecified
+}
+
+main() {
+  print(C1);
+  print(C2);
+  print(C3);
+}

LibTest/js_interop/anonymous_A06_t01.dart

@@ -0,0 +1,44 @@
+// 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 not an error if a class annotated with
+/// [anonymous] declares static members.
+/// @author sgrekhov22@gmail.com
+
+import 'dart:js_interop';
+
+@anonymous
+@staticInterop
+@JS()
+class C {
+  static String v = "v";
+  static String get g => "g";
+  static String m() => "m";
+  static void set s(String s) {}
+}
+
+main() {
+  print(C);
+}