| // Copyright (c) 2013, 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. |
| |
| import "package:expect/expect.dart"; |
| |
| class Override { |
| int hash = -1; |
| int get superHash => super.hashCode; |
| int get hashCode => hash; |
| |
| int foo() => hash; // Just some function that can be closurized. |
| |
| bool operator ==(Object other) => other is Override && other.hash == hash; |
| } |
| |
| int bar() => 42; // Some global function. |
| |
| main() { |
| var o = new Object(); |
| var hash = o.hashCode; |
| // Doesn't change. |
| Expect.equals(hash, o.hashCode); |
| Expect.equals(hash, identityHashCode(o)); |
| |
| var c = new Override(); |
| int identityHash = c.superHash; |
| hash = (identityHash == 42) ? 37 : 42; |
| c.hash = hash; |
| Expect.equals(hash, c.hashCode); |
| Expect.equals(identityHash, identityHashCode(c)); |
| |
| // These classes don't override hashCode. |
| var samples = [0, 0x10000000, 1.5, -0, null, true, false, const Object()]; |
| for (var v in samples) { |
| print(v); |
| Expect.equals(v.hashCode, identityHashCode(v)); |
| } |
| // These do, or might do, but we can still use hashCodeOf and get the same |
| // result each time. |
| samples = ["string", "", (x) => 42, c.foo, bar]; |
| for (var v in samples) { |
| print(v); |
| Expect.equals(v.hashCode, v.hashCode); |
| Expect.equals(identityHashCode(v), identityHashCode(v)); |
| } |
| } |