Language/12_Expressions/22_Equality_A03_t03.dart

/*
 * Copyright (c) 2011, 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 Evaluation of an equality expression ee of the form super == e
 * proceeds as follows:
 * • The expression e is evaluated to an object o.
 * • If either this or o is null, then ee evaluates to identical(this, o).
 *   Otherwise, ee is equivalent to the method invocation super.==(o).
 * @description Checks that if operands are not [:null:],
 * user-defined operator== will be invoked on the instance referenced by 'super'
 * @author msyabro
 * @reviewer kaigorodov
 */
import "../../Utils/expect.dart";

class TestException {}

class S {
  operator ==(other) {
    throw new TestException();
  }
}

class A extends S {
  test() {
    try {
      super == 1;
      Expect.fail("operator == was not called");
    } on TestException catch(e) {}
  }
}

main() {
  A a = new A();
  a.test();
}