// Copyright (C) 2020 Alexey Shvayka. All rights reserved. // This code is governed by the BSD license found in the LICENSE file. /*--- esid: sec-array.prototype.flat description: > TypeError is thrown if CreateDataProperty fails. (result object's "0" is non-configurable, source array gets flattened) info: | Array.prototype.flat ( [ depth ] ) [...] 6. Perform ? FlattenIntoArray(A, O, sourceLen, 0, depthNum). FlattenIntoArray ( target, source, sourceLen, start, depth [ , mapperFunction, thisArg ] ) [...] 9. Repeat, while sourceIndex < sourceLen [...] c. If exists is true, then [...] v. If shouldFlatten is true, then [...] 2. Set targetIndex to ? FlattenIntoArray(target, element, elementLen, targetIndex, depth - 1). [...] CreateDataPropertyOrThrow ( O, P, V ) [...] 3. Let success be ? CreateDataProperty(O, P, V). 4. If success is false, throw a TypeError exception. features: [Symbol.species] ---*/ var A = function(_length) { Object.defineProperty(this, "0", { set: function(_value) {}, configurable: false, }); }; var arr = [[1]]; arr.constructor = {}; arr.constructor[Symbol.species] = A; assert.throws(TypeError, function() { arr.flat(1); }); reportCompare(0, 0);