Language/Expressions/Type_Test/evaluation_t11.dart

// Copyright (c) 2016, 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.

// @dart = 2.9

/// @assertion Evaluation of the is-expression e is T proceeds as follows:
/// The expression e is evaluated to a value v.
/// Then, if T is malformed or deferred type, a dynamic error occurs.
/// Otherwise, if the interface of the class of v is a subtype of T, the
/// is-expression evaluates to true.
/// Otherwise it evaluates to false.
/// @description Checks that if the interface of the class v is a subtype of T,
/// the is-expression evaluates to true.
/// @author ngl@unipro.ru

import '../../../Utils/expect.dart';

class A {}
class B extends A {}

main() {
  Expect.isTrue(new B() is A);
  Expect.isTrue(new A() is A);
}