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- 'use strict';
- var GetIntrinsic = require('../GetIntrinsic.js');
- var $construct = GetIntrinsic('%Reflect.construct%', true);
- var DefinePropertyOrThrow = require('./DefinePropertyOrThrow');
- try {
- DefinePropertyOrThrow({}, '', { '[[Get]]': function () {} });
- } catch (e) {
- // Accessor properties aren't supported
- DefinePropertyOrThrow = null;
- }
- // https://ecma-international.org/ecma-262/6.0/#sec-isconstructor
- if (DefinePropertyOrThrow && $construct) {
- var isConstructorMarker = {};
- var badArrayLike = {};
- DefinePropertyOrThrow(badArrayLike, 'length', {
- '[[Get]]': function () {
- throw isConstructorMarker;
- },
- '[[Enumerable]]': true
- });
- module.exports = function IsConstructor(argument) {
- try {
- // `Reflect.construct` invokes `IsConstructor(target)` before `Get(args, 'length')`:
- $construct(argument, badArrayLike);
- } catch (err) {
- return err === isConstructorMarker;
- }
- };
- } else {
- module.exports = function IsConstructor(argument) {
- // unfortunately there's no way to truly check this without try/catch `new argument` in old environments
- return typeof argument === 'function' && !!argument.prototype;
- };
- }
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