old


Make the 'new' keyword optional for ES6 classes

Usage

npm install old

``js
var old = require('old')

class Class {
// ...
}

var Class2 = old(Class)

Class() // throws error
Class2() // creates an instance of Class
`

Rationale

With ES5 "constructor" functions, a common pattern is to make the new keyword optional by doing something like the following:
`js
function Foo () {
if (!(this instanceof Foo)) return new Foo()
// do constructor stuff
}
`

Recently, ES6 introduced classes to replace constructor functions. However, if these classes are instantiated without new, an error is thrown: TypeError: Class constructor Foo cannot be invoked without 'new'. This module makes new` optional, even for these ES6 classes.

Credit

- Thank you to Sorella in ##javascript (Freenode) for the clean solution
- Thanks to slikts in ##javascript for the name idea