15.2.3.6-4-21.js (1272B)
1 // Copyright (c) 2012 Ecma International. All rights reserved. 2 // This code is governed by the BSD license found in the LICENSE file. 3 4 /*--- 5 info: | 6 Step 4 of defineProperty calls the [[DefineOwnProperty]] internal method 7 of O to define the property. For non-configurable properties, step 11.a.ii 8 of [[DefineOwnProperty]] permits setting a getter if absent. 9 es5id: 15.2.3.6-4-21 10 description: > 11 Object.defineProperty permits setting a getter (if absent) of 12 non-configurable accessor properties(8.12.9 step 11.a.ii) 13 ---*/ 14 15 var o = {}; 16 17 // create an accessor property; all other attributes default to false. 18 // dummy setter 19 var setter = function(x) {} 20 var d1 = { 21 set: setter 22 }; 23 Object.defineProperty(o, "foo", d1); 24 25 // now, trying to set the getter should succeed even though [[Configurable]] 26 // on the original property will be false. Existing values of need to be preserved. 27 var getter = undefined; 28 var desc = { 29 get: getter 30 }; 31 32 Object.defineProperty(o, "foo", desc); 33 var d2 = Object.getOwnPropertyDescriptor(o, "foo"); 34 35 assert.sameValue(d2.get, getter, 'd2.get'); 36 assert.sameValue(d2.set, setter, 'd2.set'); 37 assert.sameValue(d2.configurable, false, 'd2.configurable'); 38 assert.sameValue(d2.enumerable, false, 'd2.enumerable'); 39 40 reportCompare(0, 0);