| // 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. |
| |
| // Tests that equality is allowed for receivers of specific types. |
| |
| import "package:expect/expect.dart"; |
| |
| main() { |
| const c = C(); // Does not override operator==. |
| const d = D(); // Overrides operator==. |
| |
| // Allowed if receiver is int, double, String, bool or Null, ... |
| Expect.isTrue(const T.eq(1, 1).value); |
| Expect.isTrue(const T.eq(1.5, 1.5).value); |
| Expect.isTrue(const T.eq("", "").value); |
| Expect.isTrue(const T.eq(true, true).value); |
| Expect.isTrue(const T.eq(null, null).value); |
| |
| Expect.isFalse(const T.eq(1, c).value); |
| Expect.isFalse(const T.eq(1.5, c).value); |
| Expect.isFalse(const T.eq("", c).value); |
| Expect.isFalse(const T.eq(true, c).value); |
| Expect.isFalse(const T.eq(null, c).value); |
| |
| Expect.isFalse(const T.eq(1, d).value); |
| Expect.isFalse(const T.eq(1.5, d).value); |
| Expect.isFalse(const T.eq("", d).value); |
| Expect.isFalse(const T.eq(true, d).value); |
| Expect.isFalse(const T.eq(null, d).value); |
| |
| // ... or if second operand is Null. |
| Expect.isFalse(const T.eq(1, null).value); |
| Expect.isFalse(const T.eq(1.5, null).value); |
| Expect.isFalse(const T.eq("", null).value); |
| Expect.isFalse(const T.eq(false, null).value); |
| Expect.isFalse(const T.eq(c, null).value); |
| Expect.isFalse(const T.eq(d, null).value); |
| |
| // Otherwise not allowed. |
| const T.eq(c, c); //# 01: compile-time error |
| const T.eq(c, 1); //# 02: compile-time error |
| const T.eq(c, ""); //# 03: compile-time error |
| const T.eq(E.value1, E.value2); //# 04: compile-time error |
| } |
| |
| class T { |
| final Object value; |
| const T.eq(Object? o1, Object? o2) : value = o1 == o2; |
| } |
| |
| /// Class that does not override operator==. |
| class C { |
| const C(); |
| } |
| |
| /// Class that overrides operator==. |
| class D { |
| const D(); |
| bool operator ==(Object other) => identical(this, other); |
| } |
| |
| enum E { value1, value2 } |