1 // Copyright 2009 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 // Flags: --es5_readonly 29 30 // According to ECMA-262, sections 8.6.2.2 and 8.6.2.3 you're not 31 // allowed to override read-only properties, not even if the read-only 32 // property is in the prototype chain. 33 // 34 // However, for compatibility with WebKit/JSC, we allow the overriding 35 // of read-only properties in prototype chains. 36 37 function F() {}; 38 F.prototype = Number; 39 40 var original_number_max = Number.MAX_VALUE; 41 42 // Assignment to a property which does not exist on the object itself, 43 // but is read-only in a prototype does not take effect. 44 var f = new F(); 45 assertEquals(original_number_max, f.MAX_VALUE); 46 f.MAX_VALUE = 42; 47 assertEquals(original_number_max, f.MAX_VALUE); 48 49 // Assignment to a property which does not exist on the object itself, 50 // but is read-only in a prototype does not take effect. 51 f = new F(); 52 with (f) { 53 MAX_VALUE = 42; 54 } 55 assertEquals(original_number_max, f.MAX_VALUE); 56 57 // Assignment to read-only property on the object itself is ignored. 58 Number.MAX_VALUE = 42; 59 assertEquals(original_number_max, Number.MAX_VALUE); 60 61 // G should be read-only on the global object and the assignment is 62 // ignored. 63 (function G() { 64 eval("G = 42;"); 65 assertTrue(typeof G === 'function'); 66 })(); 67
