Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1 | // Copyright 2015 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 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 5 | // Test the ES2015 @@species feature |
| 6 | |
| 7 | 'use strict'; |
| 8 | |
| 9 | // Subclasses of Array construct themselves under map, etc |
| 10 | |
| 11 | class MyArray extends Array { } |
| 12 | |
| 13 | assertEquals(MyArray, new MyArray().map(()=>{}).constructor); |
| 14 | assertEquals(MyArray, new MyArray().filter(()=>{}).constructor); |
| 15 | assertEquals(MyArray, new MyArray().slice().constructor); |
| 16 | assertEquals(MyArray, new MyArray().splice().constructor); |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 17 | assertEquals(MyArray, new MyArray().concat([1]).constructor); |
| 18 | assertEquals(1, new MyArray().concat([1])[0]); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 19 | |
| 20 | // Subclasses can override @@species to return the another class |
| 21 | |
| 22 | class MyOtherArray extends Array { |
| 23 | static get [Symbol.species]() { return MyArray; } |
| 24 | } |
| 25 | |
| 26 | assertEquals(MyArray, new MyOtherArray().map(()=>{}).constructor); |
| 27 | assertEquals(MyArray, new MyOtherArray().filter(()=>{}).constructor); |
| 28 | assertEquals(MyArray, new MyOtherArray().slice().constructor); |
| 29 | assertEquals(MyArray, new MyOtherArray().splice().constructor); |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 30 | assertEquals(MyArray, new MyOtherArray().concat().constructor); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 31 | |
| 32 | // Array methods on non-arrays return arrays |
| 33 | |
| 34 | class MyNonArray extends Array { |
| 35 | static get [Symbol.species]() { return MyObject; } |
| 36 | } |
| 37 | |
| 38 | class MyObject { } |
| 39 | |
| 40 | assertEquals(MyObject, |
| 41 | Array.prototype.map.call(new MyNonArray(), ()=>{}).constructor); |
| 42 | assertEquals(MyObject, |
| 43 | Array.prototype.filter.call(new MyNonArray(), ()=>{}).constructor); |
| 44 | assertEquals(MyObject, |
| 45 | Array.prototype.slice.call(new MyNonArray()).constructor); |
| 46 | assertEquals(MyObject, |
| 47 | Array.prototype.splice.call(new MyNonArray()).constructor); |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 48 | assertEquals(MyObject, |
| 49 | Array.prototype.concat.call(new MyNonArray()).constructor); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 50 | |
| 51 | assertEquals(undefined, |
| 52 | Array.prototype.map.call(new MyNonArray(), ()=>{}).length); |
| 53 | assertEquals(undefined, |
| 54 | Array.prototype.filter.call(new MyNonArray(), ()=>{}).length); |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 55 | assertEquals(undefined, |
| 56 | Array.prototype.concat.call(new MyNonArray(), ()=>{}).length); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 57 | // slice and splice actually do explicitly define the length for some reason |
| 58 | assertEquals(0, Array.prototype.slice.call(new MyNonArray()).length); |
| 59 | assertEquals(0, Array.prototype.splice.call(new MyNonArray()).length); |
| 60 | |
| 61 | // Cross-realm Arrays build same-realm arrays |
| 62 | |
| 63 | var realm = Realm.create(); |
| 64 | assertEquals(Array, |
| 65 | Array.prototype.map.call( |
| 66 | Realm.eval(realm, "[]"), ()=>{}).constructor); |
| 67 | assertFalse(Array === Realm.eval(realm, "[]").map(()=>{}).constructor); |
| 68 | assertFalse(Array === Realm.eval(realm, "[].map(()=>{}).constructor")); |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 69 | assertEquals(Array, |
| 70 | Array.prototype.concat.call( |
| 71 | Realm.eval(realm, "[]")).constructor); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 72 | |
| 73 | // Defaults when constructor or @@species is missing or non-constructor |
| 74 | |
| 75 | class MyDefaultArray extends Array { |
| 76 | static get [Symbol.species]() { return undefined; } |
| 77 | } |
| 78 | assertEquals(Array, new MyDefaultArray().map(()=>{}).constructor); |
| 79 | |
| 80 | class MyOtherDefaultArray extends Array { } |
| 81 | assertEquals(MyOtherDefaultArray, |
| 82 | new MyOtherDefaultArray().map(()=>{}).constructor); |
| 83 | MyOtherDefaultArray.prototype.constructor = undefined; |
| 84 | assertEquals(Array, new MyOtherDefaultArray().map(()=>{}).constructor); |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 85 | assertEquals(Array, new MyOtherDefaultArray().concat().constructor); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 86 | |
| 87 | // Exceptions propagated when getting constructor @@species throws |
| 88 | |
| 89 | class SpeciesError extends Error { } |
| 90 | class ConstructorError extends Error { } |
| 91 | class MyThrowingArray extends Array { |
| 92 | static get [Symbol.species]() { throw new SpeciesError; } |
| 93 | } |
| 94 | assertThrows(() => new MyThrowingArray().map(()=>{}), SpeciesError); |
| 95 | Object.defineProperty(MyThrowingArray.prototype, 'constructor', { |
| 96 | get() { throw new ConstructorError; } |
| 97 | }); |
| 98 | assertThrows(() => new MyThrowingArray().map(()=>{}), ConstructorError); |
| 99 | |
| 100 | // Previously unexpected errors from setting properties in arrays throw |
| 101 | |
| 102 | class FrozenArray extends Array { |
| 103 | constructor(...args) { |
| 104 | super(...args); |
| 105 | Object.freeze(this); |
| 106 | } |
| 107 | } |
| 108 | assertThrows(() => new FrozenArray([1]).map(()=>0), TypeError); |
| 109 | assertThrows(() => new FrozenArray([1]).filter(()=>true), TypeError); |
| 110 | assertThrows(() => new FrozenArray([1]).slice(0, 1), TypeError); |
| 111 | assertThrows(() => new FrozenArray([1]).splice(0, 1), TypeError); |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 112 | assertThrows(() => new FrozenArray([]).concat([1]), TypeError); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 113 | |
| 114 | // Verify call counts and constructor parameters |
| 115 | |
| 116 | var count; |
| 117 | var params; |
| 118 | class MyObservedArray extends Array { |
| 119 | constructor(...args) { |
| 120 | super(...args); |
| 121 | params = args; |
| 122 | } |
| 123 | static get [Symbol.species]() { |
| 124 | count++ |
| 125 | return this; |
| 126 | } |
| 127 | } |
| 128 | |
| 129 | count = 0; |
| 130 | params = undefined; |
| 131 | assertEquals(MyObservedArray, |
| 132 | new MyObservedArray().map(()=>{}).constructor); |
| 133 | assertEquals(1, count); |
| 134 | assertArrayEquals([0], params); |
| 135 | |
| 136 | count = 0; |
| 137 | params = undefined; |
| 138 | assertEquals(MyObservedArray, |
| 139 | new MyObservedArray().filter(()=>{}).constructor); |
| 140 | assertEquals(1, count); |
| 141 | assertArrayEquals([0], params); |
| 142 | |
| 143 | count = 0; |
| 144 | params = undefined; |
| 145 | assertEquals(MyObservedArray, |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 146 | new MyObservedArray().concat().constructor); |
| 147 | assertEquals(1, count); |
| 148 | assertArrayEquals([0], params); |
| 149 | |
| 150 | count = 0; |
| 151 | params = undefined; |
| 152 | assertEquals(MyObservedArray, |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 153 | new MyObservedArray().slice().constructor); |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 154 | assertEquals(1, count); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 155 | assertArrayEquals([0], params); |
| 156 | |
| 157 | count = 0; |
| 158 | params = undefined; |
| 159 | assertEquals(MyObservedArray, |
| 160 | new MyObservedArray().splice().constructor); |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 161 | assertEquals(1, count); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 162 | assertArrayEquals([0], params); |
| 163 | |
| 164 | // @@species constructor can be a Proxy, and the realm access doesn't |
| 165 | // crash |
| 166 | |
| 167 | class MyProxyArray extends Array { } |
| 168 | let ProxyArray = new Proxy(MyProxyArray, {}); |
| 169 | MyProxyArray.constructor = ProxyArray; |
| 170 | |
| 171 | assertEquals(MyProxyArray, new ProxyArray().map(()=>{}).constructor); |