Created PreviewModal test

test/short-urls/helpers/PreviewModal.test.js

@@ -0,0 +1,28 @@
+import React from 'react';
+import { shallow } from 'enzyme';
+import PreviewModal from '../../../src/short-urls/helpers/PreviewModal';
+import ExternalLink from '../../../src/utils/ExternalLink';
+
+describe('<PreviewModal />', () => {
+  let wrapper;
+  const url = 'https://doma.in/abc123';
+
+  beforeEach(() => {
+    wrapper = shallow(<PreviewModal url={url} />);
+  });
+  afterEach(() => wrapper.unmount());
+
+  it('shows an external link to the URL', () => {
+    const externalLink = wrapper.find(ExternalLink);
+
+    expect(externalLink).toHaveLength(1);
+    expect(externalLink.prop('href')).toEqual(url);
+  });
+
+  it('displays an image with the preview of the URL', () => {
+    const img = wrapper.find('img');
+
+    expect(img).toHaveLength(1);
+    expect(img.prop('src')).toEqual(`${url}/preview`);
+  });
+});