router with bundle loader

router.diff

import Backbone from 'backbone';
import $ from 'jquery';

import AppFinder from './app_finder_test';

export default Backbone.Router.extend({
  routes: {
    '': 'home',
    'main_app_part': 'mainAppPart',
    '*handleMissingRoute': 'handle404'
  },

  home() {
    $('#app').html("You're on the home page");
  },

  mainAppPart() {
    $('#app').html("You're viewing part of the main app, no async bundle loading here");
  },

  handle404(path) {
    const mini_app_name = AppFinder(path);

    if (mini_app_name) {
+     const handler = require('bundle!./apps/' + mini_app_name + '/index.js');
-     require.ensure([], require => {
+     handler(bundle => {
-       const App = require('./apps/' + mini_app_name + '/index.js').default;
+       const App = bundle.default;
        App();
        Backbone.history.loadUrl();
      });
    } else {
      alert('404');
    }
  },
});