lepu-test-platform-web/node_modules/es-abstract/2016/ArraySpeciesCreate.js

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'use strict';
var GetIntrinsic = require('../GetIntrinsic');
var $Array = GetIntrinsic('%Array%');
var $species = GetIntrinsic('%Symbol.species%', true);
var $TypeError = GetIntrinsic('%TypeError%');
var Get = require('./Get');
var IsArray = require('./IsArray');
var IsConstructor = require('./IsConstructor');
var IsInteger = require('./IsInteger');
var Type = require('./Type');
// https://ecma-international.org/ecma-262/6.0/#sec-arrayspeciescreate
module.exports = function ArraySpeciesCreate(originalArray, length) {
if (!IsInteger(length) || length < 0) {
throw new $TypeError('Assertion failed: length must be an integer >= 0');
}
var len = length === 0 ? 0 : length;
var C;
var isArray = IsArray(originalArray);
if (isArray) {
C = Get(originalArray, 'constructor');
// TODO: figure out how to make a cross-realm normal Array, a same-realm Array
// if (IsConstructor(C)) {
// if C is another realm's Array, C = undefined
// Object.getPrototypeOf(Object.getPrototypeOf(Object.getPrototypeOf(Array))) === null ?
// }
if ($species && Type(C) === 'Object') {
C = Get(C, $species);
if (C === null) {
C = void 0;
}
}
}
if (typeof C === 'undefined') {
return $Array(len);
}
if (!IsConstructor(C)) {
throw new $TypeError('C must be a constructor');
}
return new C(len); // Construct(C, len);
};