import Image from './image'; const imageHtml = ''; describe('Image', () => { let image; beforeEach(() => { document.body.innerHTML = imageHtml; image = document.querySelector('img'); }); it('Should initialize', () => { const img = new Image(image); expect(img).toBeInstanceOf(Image); }); it('Should store a reference to the image element', () => { const img = new Image(image); expect(img.image).toBe(image); }); test('fadeIn should set the element opacity to 0', () => { const img = new Image(image); img.fadeIn(); expect(img.image.style.opacity).toBe('0'); }); test('showImage should set the element opacity to 1', () => { const img = new Image(image); img.showImage(); expect(img.image.style.opacity).toBe('1'); }); });