// Copyright (c) 2019, 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 A class has a set of direct superinterfaces. This set includes
/// the interface of its superclass and the interfaces specified in the the
/// implements clause of the class.
/// interfaces:
///   implements typeList
/// ;
/// @description Checks that a class can indeed specify one or more
/// superinterfaces using the implements clause and an instance of this class
/// will also be an instance of those interfaces as well as any and all of its
/// superclasses' superinterfaces.
/// @author sgrekhov@unipro.ru

import "../../../Utils/expect.dart";

abstract class IA {}
typedef IAAlias = IA;
class A implements IAAlias {}
abstract class IB {}
typedef IBAlias = IB;
class B extends IAAlias implements IBAlias {}
abstract class IC {}
typedef ICAlias = IC;
abstract class ID {}
typedef IDAlias = ID;
class C extends B implements ICAlias, IDAlias {}

main() {
  C c = new C();
  Expect.isTrue(c is IA);
  Expect.isTrue(c is IB);
  Expect.isTrue(c is IC);
  Expect.isTrue(c is ID);
}