Example of WP modules object

wp-modules.js

// new modules object introduction
( function( window, undefined ) {

  window.wp = window.wp || {};
  window.wp.modules = window.wp.modules || {};
  
} )( window );

// example Mediator module
wp.modules.Mediator = ( function( window, undefined ) {
  
  function Mediator() {
    this.topics = {};
  }
  
  Mediator.prototype.publish = function publish() {
    //...
  };
  
  Mediator.prototype.subscribe = function subscribe() {
    //...
  };
  
  Mediator.prototype.unsubscribe = function unsubscribe() {
    //...
  };
  
  return Mediator;
  
} )( window );

// now we introduce a global version of the Mediator that can be used to communicate
// across features of WordPress, ie. - Heartbeat API to Media Modal
wp.mediator = new wp.modules.Mediator();

// if someone wanted to use the mediator within their individual component, say media modal, they could
// do so like this:
( function( window, undefined ) {
  
  // all the fake module code for media modal goes here within a public scope
  
  // we need a mediator so instead of re-implementing, we can make use of the modules already there
  // in the event that i'm unsure of what modules there are, I can `console.log( window.wp.modules );`
  
  var myPrivateFeatureMediator = new window.wp.modules.Mediator();
  
  // then internally, we can use this mediator to communicate with the different pieces of this
  // feature so we don't pollute the global traffic via the use of `wp.mediator`
  
} )( window );

Going to think about this for a bit, but in principle I prefer

( function( wp, undefined ) {

  // Clunky to have to `window.` for everything; if you're
  // passing something in you should pass in the thing
  // that you actually want imo

} )( window.wp );