discourse/app/assets/javascripts/wizard/test/helpers/start-app.js.es6

import Wizard from 'wizard/wizard';
import initializer from 'wizard/initializers/load-helpers';

let app;
let started = false;

export default function() {
  Ember.run(() => app = Wizard.create({ rootElement: '#ember-testing' }));

  if (!started) {
    initializer.initialize(app);
    app.start();
    started = true;
  }
  app.setupForTesting();
  app.injectTestHelpers();
  return app;
}