add test for shortcuts_dashboard_navigation.js

app/assets/javascripts/shortcuts_dashboard_navigation.js

+import { visitUrl } from './lib/utils/url_utility';
+
 /**
  * Helper function that finds the href of the fiven selector and updates the location.
  *
  * @param  {String} selector
  */
-export default selector => {
+export default function findAndFollowLink(selector) {
   const element = document.querySelector(selector);
   const link = element && element.getAttribute('href');
 
   if (link) {
-    window.location = link;
+    visitUrl(link);
   }
-};
+}

spec/javascripts/shortcuts_dashboard_navigation_spec.js

+import findAndFollowLink from '~/shortcuts_dashboard_navigation';
+import * as urlUtility from '~/lib/utils/url_utility';
+
+describe('findAndFollowLink', () => {
+  it('visits a link when the selector exists', () => {
+    const href = '/some/path';
+    const locationSpy = spyOn(urlUtility, 'visitUrl');
+
+    setFixtures(`<a class="my-shortcut" href="${href}">link</a>`);
+
+    findAndFollowLink('.my-shortcut');
+
+    expect(locationSpy).toHaveBeenCalledWith(href);
+  });
+
+  it('does not throw an exception when the selector does not exist', () => {
+    const locationSpy = spyOn(urlUtility, 'visitUrl');
+
+    // this should not throw an exception
+    findAndFollowLink('.this-selector-does-not-exist');
+
+    expect(locationSpy).not.toHaveBeenCalled();
+  });
+});