Language/Expressions/Equality/evaluation_t04.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 e1 == e2
/// proceeds as follows:
/// •  The expression e1 is evaluated to an object o1.
/// •  The expression e2 is evaluated to an object o2.
/// •  If either o1 or o2 is null, then ee evaluates to true if both o1 and o2
///    are null and to false otherwise. Otherwise,
/// •  ee is equivalent to the method invocation o1.==(o2).
/// @description Checks that if operands are not null ee is equivalent to the
/// method invocation o1.==(o2).
/// @author msyabro


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

class TestException {}

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

main() {
  A a = new A();
  try {
    a == 1;
    Expect.fail("operator== was not called");
  } on TestException catch (e) {}
}