1 // Copyright 2010 the V8 project authors. All rights reserved. 2 // Redistribution and use in source and binary forms, with or without 3 // modification, are permitted provided that the following conditions are 4 // met: 5 // 6 // * Redistributions of source code must retain the above copyright 7 // notice, this list of conditions and the following disclaimer. 8 // * Redistributions in binary form must reproduce the above 9 // copyright notice, this list of conditions and the following 10 // disclaimer in the documentation and/or other materials provided 11 // with the distribution. 12 // * Neither the name of Google Inc. nor the names of its 13 // contributors may be used to endorse or promote products derived 14 // from this software without specific prior written permission. 15 // 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28 // Tests the Object.preventExtensions method - ES 15.2.3.10 29 30 // Flags: --allow-natives-syntax 31 32 33 var obj1 = {}; 34 // Extensible defaults to true. 35 assertTrue(Object.isExtensible(obj1)); 36 Object.preventExtensions(obj1); 37 38 // Make sure the is_extensible flag is set. 39 assertFalse(Object.isExtensible(obj1)); 40 obj1.x = 42; 41 assertEquals(undefined, obj1.x); 42 43 // Try adding a new element. 44 obj1[1] = 42; 45 assertEquals(undefined, obj1[1]); 46 47 48 // Try when the object has an existing property. 49 var obj2 = {}; 50 assertTrue(Object.isExtensible(obj2)); 51 obj2.x = 42; 52 assertEquals(42, obj2.x); 53 assertTrue(Object.isExtensible(obj2)); 54 55 Object.preventExtensions(obj2); 56 assertEquals(42, obj2.x); 57 58 obj2.y = 42; 59 // obj2.y should still be undefined. 60 assertEquals(undefined, obj2.y); 61 // Make sure we can still write values to obj.x. 62 obj2.x = 43; 63 assertEquals(43, obj2.x) 64 65 obj2.y = new function() { return 42; }; 66 // obj2.y should still be undefined. 67 assertEquals(undefined, obj2.y); 68 assertEquals(43, obj2.x) 69 70 try { 71 Object.defineProperty(obj2, "y", {value: 42}); 72 } catch (e) { 73 assertTrue(/object is not extensible/.test(e)); 74 } 75 76 // obj2.y should still be undefined. 77 assertEquals(undefined, obj2.y); 78 assertEquals(43, obj2.x); 79 80 obj2[1] = 42; 81 assertEquals(undefined, obj2[1]); 82 83 var arr = new Array(); 84 arr[1] = 10; 85 86 Object.preventExtensions(arr); 87 88 arr[2] = 42; 89 assertEquals(10, arr[1]); 90 91 // We should still be able to change existing elements. 92 arr[1]= 42; 93 assertEquals(42, arr[1]); 94 95 96 // Test the the extensible flag is not inherited. 97 var parent = {}; 98 parent.x = 42; 99 Object.preventExtensions(parent); 100 101 var child = Object.create(parent); 102 103 // We should be able to add new properties to the child object. 104 child.y = 42; 105 106 // This should have no influence on the parent class. 107 parent.y = 29; 108 109 110 // Test that attributes on functions are also handled correctly. 111 function foo() { 112 return 42; 113 } 114 115 Object.preventExtensions(foo); 116 117 foo.x = 29; 118 assertEquals(undefined, foo.x); 119 120 // when Object.isExtensible(o) === false 121 // assignment should return right hand side value 122 var o = Object.preventExtensions({}); 123 var v = o.v = 50; 124 assertEquals(undefined, o.v); 125 assertEquals(50, v); 126 127 // test same behavior as above, but for integer properties 128 var n = o[0] = 100; 129 assertEquals(undefined, o[0]); 130 assertEquals(100, n); 131 132 // Fast properties should remain fast 133 obj = { x: 42, y: 'foo' }; 134 assertTrue(%HasFastProperties(obj)); 135 Object.preventExtensions(obj); 136 assertFalse(Object.isExtensible(obj)); 137 assertFalse(Object.isSealed(obj)); 138 assertTrue(%HasFastProperties(obj)); 139 140 // Non-extensible objects should share maps where possible 141 obj = { prop1: 1, prop2: 2 }; 142 obj2 = { prop1: 3, prop2: 4 }; 143 assertTrue(%HaveSameMap(obj, obj2)); 144 Object.preventExtensions(obj); 145 Object.preventExtensions(obj2); 146 assertFalse(Object.isExtensible(obj)); 147 assertFalse(Object.isExtensible(obj2)); 148 assertFalse(Object.isSealed(obj)); 149 assertFalse(Object.isSealed(obj2)); 150 assertTrue(%HaveSameMap(obj, obj2)); 151 152 // Non-extensible objects should share maps even when they have elements 153 obj = { prop1: 1, prop2: 2, 75: 'foo' }; 154 obj2 = { prop1: 3, prop2: 4, 150: 'bar' }; 155 assertTrue(%HaveSameMap(obj, obj2)); 156 Object.preventExtensions(obj); 157 Object.preventExtensions(obj2); 158 assertFalse(Object.isExtensible(obj)); 159 assertFalse(Object.isExtensible(obj2)); 160 assertFalse(Object.isSealed(obj)); 161 assertFalse(Object.isSealed(obj2)); 162 assertTrue(%HaveSameMap(obj, obj2)); 163
