tests/language/sealed_class/sealed_class_extend_error_test.dart

// Copyright (c) 2022, 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.

// Error when attempting to extend a sealed class outside of its library.

import 'sealed_class_extend_lib.dart';

abstract class OutsideA extends SealedClass {}
//                              ^^^^^^^^^^^
// [analyzer] COMPILE_TIME_ERROR.INVALID_USE_OF_TYPE_OUTSIDE_LIBRARY
// [cfe] The class 'SealedClass' can't be extended, implemented, or mixed in outside of its library because it's a sealed class.

class OutsideB extends SealedClass {
//                     ^^^^^^^^^^^
// [analyzer] COMPILE_TIME_ERROR.INVALID_USE_OF_TYPE_OUTSIDE_LIBRARY
// [cfe] The class 'SealedClass' can't be extended, implemented, or mixed in outside of its library because it's a sealed class.
  int foo = 2;
  int bar(int value) => value;
}