JS Bin// source http://jsbin.com/dabebax

modulePatternDemo.js

//module test
'use strict';

//the namespace that will be exported
var myModule = {};

//wrapper function to export all as one namespace
(function wrapper(exports) {
    (function existsModule(exports) {

        var api = {
            moduleExists: function moduleExists() {
                return true;
            }
        };

        Object.assign(exports, api);
    })(typeof exports === 'undefined' ? window : exports);
})(myModule);

console.log(myModule.moduleExists);

Module Pattern