// Copyright (c) 2012 Ecma International. All rights reserved. // This code is governed by the BSD license found in the LICENSE file. /*--- info: > 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. es5id: 15.2.3.6-4-16 description: > Object.defineProperty throws TypeError when relaxing [[Writable]] on non-configurable data properties includes: [runTestCase.js] ---*/ 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);