// Copyright (C) 2020 Alexey Shvayka. All rights reserved. // This code is governed by the BSD license found in the LICENSE file. /*--- author: André Bargull esid: sec-arraysetlength description: > [[Value]] is coerced to number before descriptor validation. info: | ArraySetLength ( A, Desc ) [...] 3. Let newLen be ? ToUint32(Desc.[[Value]]). 4. Let numberLen be ? ToNumber(Desc.[[Value]]). [...] 7. Let oldLenDesc be OrdinaryGetOwnProperty(A, "length"). [...] 11. If newLen ≥ oldLen, then a. Return OrdinaryDefineOwnProperty(A, "length", newLenDesc). OrdinaryDefineOwnProperty ( O, P, Desc ) [...] 3. Return ValidateAndApplyPropertyDescriptor(O, P, extensible, Desc, current). ValidateAndApplyPropertyDescriptor ( O, P, extensible, Desc, current ) [...] 7. Else if IsDataDescriptor(current) and IsDataDescriptor(Desc) are both true, then a. If current.[[Configurable]] is false and current.[[Writable]] is false, then i. If Desc.[[Writable]] is present and Desc.[[Writable]] is true, return false. features: [Reflect] ---*/ var array = [1, 2]; var valueOfCalls = 0; var length = { valueOf: function() { valueOfCalls += 1; if (valueOfCalls !== 1) { // skip first coercion at step 3 Object.defineProperty(array, "length", {writable: false}); } return array.length; }, }; assert.throws(TypeError, function() { Object.defineProperty(array, "length", {value: length, writable: true}); }, 'Object.defineProperty(array, "length", {value: length, writable: true}) throws a TypeError exception'); assert.sameValue(valueOfCalls, 2, 'The value of valueOfCalls is expected to be 2'); array = [1, 2]; valueOfCalls = 0; assert( !Reflect.defineProperty(array, "length", {value: length, writable: true}), 'The value of !Reflect.defineProperty(array, "length", {value: length, writable: true}) is expected to be true' ); assert.sameValue(valueOfCalls, 2, 'The value of valueOfCalls is expected to be 2'); reportCompare(0, 0);