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4 years ago
'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');
};