import '~/behaviors/autosize'; function load() { document.dispatchEvent(new Event('DOMContentLoaded')); } jest.mock('~/helpers/startup_css_helper', () => { return { waitForCSSLoaded: jest.fn().mockImplementation(cb => cb.apply()), }; }); describe('Autosize behavior', () => { beforeEach(() => { setFixtures(''); }); it('is applied to the textarea', () => { load(); const textarea = document.querySelector('textarea'); expect(textarea.classList).toContain('js-autosize-initialized'); }); });