// 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 An interface has a set of direct superinterfaces.
/// An interface J is a superinterface of an interface I iff either J is a
/// direct superinterface of I or J is a superinterface of a direct
/// superinterface of I.
/// @description Checks that it is a compile-time error if the chain of
/// superinterfaces forms a circular dependency. Test type aliases
/// @author sgrekhov@unipro.ru

// SharedOptions=--enable-experiment=nonfunction-type-aliases

abstract class C implements A {}
//             ^
// [analyzer] unspecified
// [cfe] unspecified
abstract class B implements C {}
//             ^
// [analyzer] unspecified
// [cfe] unspecified

typedef BAlias = B;

abstract class A implements BAlias {}
//             ^
// [analyzer] unspecified
// [cfe] unspecified

class D implements A {}
//    ^
// [cfe] unspecified

main() {
  new D();
}