File Content: ArrayCreate.js 'use strict'; var GetIntrinsic = require('get-intrinsic'); var $ArrayPrototype = GetIntrinsic('%Array.prototype%'); var $RangeError = GetIntrinsic('%RangeError%'); var $SyntaxError = GetIntrinsic('%SyntaxError%'); var $TypeError = GetIntrinsic('%TypeError%'); var IsInteger = require('./IsInteger'); var MAX_ARRAY_LENGTH = Math.pow(2, 32) - 1; var $setProto = GetIntrinsic('%Object.setPrototypeOf%', true) || ( // eslint-disable-next-line no-proto, no-negated-condition [].__proto__ !== $ArrayPrototype ? null : function (O, proto) { O.__proto__ = proto; // eslint-disable-line no-proto, no-param-reassign return O; } ); // https://ecma-international.org/ecma-262/6.0/#sec-arraycreate module.exports = function ArrayCreate(length) { if (!IsInteger(length) || length < 0) { throw new $TypeError('Assertion failed: `length` must be an integer Number >= 0'); } if (length > MAX_ARRAY_LENGTH) { throw new $RangeError('length is greater than (2**32 - 1)'); } var proto = arguments.length > 1 ? arguments[1] : $ArrayPrototype; var A = []; // steps 5 - 7, and 9 if (proto !== $ArrayPrototype) { // step 8 if (!$setProto) { throw new $SyntaxError('ArrayCreate: a `proto` argument that is not `Array.prototype` is not supported in an environment that does not support setting the [[Prototype]]'); } $setProto(A, proto); } if (length !== 0) { // bypasses the need for step 2 A.length = length; } /* step 10, the above as a shortcut for the below OrdinaryDefineOwnProperty(A, 'length', { '[[Configurable]]': false, '[[Enumerable]]': false, '[[Value]]': length, '[[Writable]]': true }); */ return A; }; Submit