Restore image fade in functionality

js/image.spec.js

@@ -0,0 +1,35 @@
+import Image from './image';
+
+const imageHtml = '<img src="foo.jpg"></img>';
+
+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');
+  });
+});
+