/// Copyright (c) 2012 Ecma International. All rights reserved. /// Ecma International makes this code available under the terms and conditions set /// forth on http://hg.ecmascript.org/tests/test262/raw-file/tip/LICENSE (the /// "Use Terms"). Any redistribution of this code must retain the above /// copyright and this notice and otherwise comply with the Use Terms. /** * Step 4 of defineProperty calls the [[DefineOwnProperty]] internal method * of O to define the property. For non-configurable properties, step 10.a.i * of [[DefineOwnProperty]] rejects if relaxing the [[Writable]] attribute. * * @path ch15/15.2/15.2.3/15.2.3.6/15.2.3.6-4-16.js * @description Object.defineProperty throws TypeError when relaxing [[Writable]] on non-configurable data properties */ function testcase() { var o = {}; // create a data valued property; all other attributes default to false. var d1 = { value: 101 }; Object.defineProperty(o, "foo", d1); // now, relaxing [[Writable]] on "foo" should fail, since both // [[Configurable]] and [[Writable]] on the original property will be false. var desc = { value: 101, writable: true }; try { Object.defineProperty(o, "foo", desc); } catch (e) { if (e instanceof TypeError) { // the property should remain unchanged. var d2 = Object.getOwnPropertyDescriptor(o, "foo"); if (d2.value === 101 && d2.writable === false && d2.enumerable === false && d2.configurable === false) { return true; } } } } runTestCase(testcase);