| /* |
| * 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 The [==] operator in constant expressions was defined such that |
| * [e1 != null] was only allowed if [e1] had one of the "primitive" system |
| * types. Users had to rewrite their code to [!identical(e1, null)]. This was |
| * changed so that the [==] expression is always allowed as long as one of the |
| * operands is [null]. |
| * @description Checks that [==] operator is allowed if one of the operands is |
| * [null] in potentially constant or compile-time constant. |
| * @author iarkh@unipro.ru |
| */ |
| // SharedOptions=--enable-experiment=constant-update-2018 |
| import "../../Utils/expect.dart"; |
| |
| const str1 = "test"; |
| const str2 = null; |
| |
| class MyClass { |
| final String option; |
| const MyClass(String str) : assert(str == null), this.option = "OK"; |
| } |
| |
| main() { |
| const bool res1 = (str1 == null); |
| Expect.isFalse(res1); |
| |
| const bool res2 = (str2 == null); |
| Expect.isTrue(res2); |
| |
| const MyClass c = MyClass(null); |
| Expect.equals("OK", c.option); |
| } |