source: imaps-frontend/node_modules/es-abstract/2018/IsConstructor.js@ d565449

'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://262.ecma-international.org/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;
        };
}