SpeciesConstructor.js

'use strict';

var GetIntrinsic = require('../GetIntrinsic');

var $species = GetIntrinsic('%Symbol.species%', true);
var $TypeError = GetIntrinsic('%TypeError%');

var IsConstructor = require('./IsConstructor');
var Type = require('./Type');

// https://ecma-international.org/ecma-262/6.0/#sec-speciesconstructor

module.exports = function SpeciesConstructor(O, defaultConstructor) {
	if (Type(O) !== 'Object') {
		throw new $TypeError('Assertion failed: Type(O) is not Object');
	}
	var C = O.constructor;
	if (typeof C === 'undefined') {
		return defaultConstructor;
	}
	if (Type(C) !== 'Object') {
		throw new $TypeError('O.constructor is not an Object');
	}
	var S = $species ? C[$species] : void 0;
	if (S == null) {
		return defaultConstructor;
	}
	if (IsConstructor(S)) {
		return S;
	}
	throw new $TypeError('no constructor found');
};