Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame^] | 1 | // Copyright 2014 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | // Based on Mozilla Array.of() tests at http://dxr.mozilla.org/mozilla-central/source/js/src/jit-test/tests/collections |
| 6 | |
| 7 | // Flags: --harmony-arrays |
| 8 | |
| 9 | |
| 10 | |
| 11 | // Array.of makes real arrays. |
| 12 | |
| 13 | function check(a) { |
| 14 | assertEquals(Object.getPrototypeOf(a), Array.prototype); |
| 15 | assertEquals(Array.isArray(a), true); |
| 16 | a[9] = 9; |
| 17 | assertEquals(a.length, 10); |
| 18 | } |
| 19 | |
| 20 | |
| 21 | check(Array.of()); |
| 22 | check(Array.of(0)); |
| 23 | check(Array.of(0, 1, 2)); |
| 24 | var f = Array.of; |
| 25 | check(f()); |
| 26 | |
| 27 | |
| 28 | // Array.of basics |
| 29 | |
| 30 | var a = Array.of(); |
| 31 | |
| 32 | assertEquals(a.length, 0); |
| 33 | a = Array.of(undefined, null, 3.14, []); |
| 34 | assertEquals(a, [undefined, null, 3.14, []]); |
| 35 | a = []; |
| 36 | for (var i = 0; i < 1000; i++) |
| 37 | a[i] = i; |
| 38 | assertEquals(Array.of.apply(null, a), a); |
| 39 | |
| 40 | |
| 41 | // Array.of does not leave holes |
| 42 | |
| 43 | assertEquals(Array.of(undefined), [undefined]); |
| 44 | assertEquals(Array.of(undefined, undefined), [undefined, undefined]); |
| 45 | assertEquals(Array.of.apply(null, [,,undefined]), [undefined, undefined, undefined]); |
| 46 | assertEquals(Array.of.apply(null, Array(4)), [undefined, undefined, undefined, undefined]); |
| 47 | |
| 48 | |
| 49 | // Array.of can be transplanted to other classes. |
| 50 | |
| 51 | var hits = 0; |
| 52 | function Bag() { |
| 53 | hits++; |
| 54 | } |
| 55 | Bag.of = Array.of; |
| 56 | |
| 57 | hits = 0; |
| 58 | var actual = Bag.of("zero", "one"); |
| 59 | assertEquals(hits, 1); |
| 60 | |
| 61 | hits = 0; |
| 62 | var expected = new Bag; |
| 63 | expected[0] = "zero"; |
| 64 | expected[1] = "one"; |
| 65 | expected.length = 2; |
| 66 | assertEquals(areSame(actual, expected), true); |
| 67 | |
| 68 | hits = 0; |
| 69 | actual = Array.of.call(Bag, "zero", "one"); |
| 70 | assertEquals(hits, 1); |
| 71 | assertEquals(areSame(actual, expected), true); |
| 72 | |
| 73 | function areSame(object, array) { |
| 74 | var result = object.length == array.length; |
| 75 | for (var i = 0; i < object.length; i++) { |
| 76 | result = result && object[i] == array[i]; |
| 77 | } |
| 78 | return result; |
| 79 | } |
| 80 | |
| 81 | |
| 82 | // Array.of does not trigger prototype setters. |
| 83 | // (It defines elements rather than assigning to them.) |
| 84 | |
| 85 | var status = "pass"; |
| 86 | Object.defineProperty(Array.prototype, "0", {set: function(v) {status = "FAIL 1"}}); |
| 87 | assertEquals(Array.of(1)[0], 1); |
| 88 | assertEquals(status, "pass"); |
| 89 | |
| 90 | Object.defineProperty(Bag.prototype, "0", {set: function(v) {status = "FAIL 2"}}); |
| 91 | assertEquals(Bag.of(1)[0], 1); |
| 92 | assertEquals(status, "pass"); |
| 93 | |
| 94 | |
| 95 | // Array.of passes the number of arguments to the constructor it calls. |
| 96 | |
| 97 | var hits = 0; |
| 98 | |
| 99 | function Herd(n) { |
| 100 | assertEquals(arguments.length, 1); |
| 101 | assertEquals(n, 5); |
| 102 | hits++; |
| 103 | } |
| 104 | |
| 105 | Herd.of = Array.of; |
| 106 | Herd.of("sheep", "cattle", "elephants", "whales", "seals"); |
| 107 | assertEquals(hits, 1); |
| 108 | |
| 109 | |
| 110 | // Array.of calls a "length" setter if one is present. |
| 111 | |
| 112 | var hits = 0; |
| 113 | var lastObj = null, lastVal = undefined; |
| 114 | function setter(v) { |
| 115 | hits++; |
| 116 | lastObj = this; |
| 117 | lastVal = v; |
| 118 | } |
| 119 | |
| 120 | // when the setter is on the new object |
| 121 | function Pack() { |
| 122 | Object.defineProperty(this, "length", {set: setter}); |
| 123 | } |
| 124 | Pack.of = Array.of; |
| 125 | var pack = Pack.of("wolves", "cards", "cigarettes", "lies"); |
| 126 | assertEquals(lastObj, pack); |
| 127 | assertEquals(lastVal, 4); |
| 128 | |
| 129 | // when the setter is on the new object's prototype |
| 130 | function Bevy() {} |
| 131 | Object.defineProperty(Bevy.prototype, "length", {set: setter}); |
| 132 | Bevy.of = Array.of; |
| 133 | var bevy = Bevy.of("quail"); |
| 134 | assertEquals(lastObj, bevy); |
| 135 | assertEquals(lastVal, 1); |
| 136 | |
| 137 | |
| 138 | // Array.of does a strict assignment to the new object's .length. |
| 139 | // The assignment is strict even if the code we're calling from is not strict. |
| 140 | |
| 141 | function Empty() {} |
| 142 | Empty.of = Array.of; |
| 143 | Object.defineProperty(Empty.prototype, "length", {get: function() { return 0; }}); |
| 144 | |
| 145 | var nothing = new Empty; |
| 146 | nothing.length = 2; // no exception; this is not a strict mode assignment |
| 147 | |
| 148 | assertThrows(function() { Empty.of(); }, TypeError); |
| 149 | |
| 150 | |
| 151 | // Check superficial features of Array.of. |
| 152 | |
| 153 | var desc = Object.getOwnPropertyDescriptor(Array, "of"); |
| 154 | |
| 155 | assertEquals(desc.configurable, true); |
| 156 | assertEquals(desc.enumerable, false); |
| 157 | assertEquals(desc.writable, true); |
| 158 | assertEquals(Array.of.length, 0); |
| 159 | assertThrows(function() { new Array.of() }, TypeError); // not a constructor |
| 160 | |
| 161 | // When the this-value passed in is not a constructor, the result is an array. |
| 162 | [undefined, null, false, "cow"].forEach(function(val) { |
| 163 | assertEquals(Array.isArray(Array.of(val)), true); |
| 164 | }); |