1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
|
// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Check that @@isConcatSpreadable is checked when set on Object.prototype
"use strict"
var array = [1, 2, 3];
var object = {length: 1, '0': 'a'};
function testConcatDefaults() {
assertEquals(array, [].concat(array));
assertEquals(array, array.concat([]));
assertEquals([1, 2, 3, 1, 2, 3], array.concat(array));
assertEquals([object], [].concat(object));
assertEquals([1, 2, 3, object], array.concat(object));
assertEquals([object], Array.prototype.concat.call(object,[]));
assertEquals([object, 1, 2, 3], Array.prototype.concat.call(object, array));
assertEquals([object, object], Array.prototype.concat.call(object, object));
}
testConcatDefaults();
var concatSpreadable = false;
Object.defineProperty(Array.prototype, Symbol.isConcatSpreadable, {
get() { return concatSpreadable },
configurable: true
});
assertEquals([[], array], [].concat(array));
assertEquals([array, []], array.concat([]));
assertEquals([array, array], array.concat(array));
assertEquals([[], object], [].concat(object));
assertEquals([array, object], array.concat(object));
assertEquals([object, []], Array.prototype.concat.call(object,[]));
assertEquals([object, array], Array.prototype.concat.call(object, array));
assertEquals([object, object], Array.prototype.concat.call(object, object));
concatSpreadable = true;
assertEquals(array, [].concat(array));
assertEquals(array, array.concat([]));
assertEquals([1, 2, 3, 1, 2, 3], array.concat(array));
assertEquals([object], [].concat(object));
assertEquals([1, 2, 3, object], array.concat(object));
assertEquals([object], Array.prototype.concat.call(object,[]));
assertEquals([object, 1, 2, 3], Array.prototype.concat.call(object, array));
assertEquals([object, object], Array.prototype.concat.call(object, object));
delete Array.prototype[Symbol.isConcatSpreadable];
testConcatDefaults();
|
