How to get multiple instances of module in node.js?

Question

In nodejs modules are singletons. I have created a module that takes configuration object and return some object. But at last I will be having single instance of the module. How to have multiple instances for different configurations?(each time they require, it should be different instance. How to achieve this?)

Answer 1

Export a constructor and don't have implicit state:

Your current code looks something like:

module.exports = { ..}; // some object

Instead export a constructor:

module.exports = function(){
    // initialize module here, no global variables
    return { .. };
};

Answer 2

Return only constructors and have a dedicated module for the singletons:

lib/user.js:

module.exports = function () { ... }

lib/currentUser.js:

module.exports = new (require('./user'))();