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

const CustomWizard = requirejs("discourse/plugins/discourse-custom-wizard/wizard/application").default;
const initializer = requirejs("discourse/plugins/discourse-custom-wizard/wizard/lib/initialize/wizard").default;
const siteSettings = requirejs("discourse/plugins/discourse-custom-wizard/wizard/tests/fixtures/site-settings").default;
const { cloneJSON } = requirejs("discourse-common/lib/object").default;

let app;

export default function () {
  app = CustomWizard.create({ rootElement: "#ember-testing" });
  app.start();

  app.SiteSettings = cloneJSON(siteSettings);
  initializer.initialize(app);

  app.setupForTesting();
  app.injectTestHelpers();

  return app;
}