Added required code coverage for jest

test/app/App.test.tsx

@@ -0,0 +1,50 @@
+import { shallow, ShallowWrapper } from 'enzyme';
+import { Route } from 'react-router-dom';
+import { Mock } from 'ts-mockery';
+import { Settings } from '../../src/settings/reducers/settings';
+import appFactory from '../../src/app/App';
+import { AppUpdateBanner } from '../../src/common/AppUpdateBanner';
+
+describe('<App />', () => {
+  let wrapper: ShallowWrapper;
+  const MainHeader = () => null;
+  const ShlinkVersions = () => null;
+
+  beforeEach(() => {
+    const App = appFactory(MainHeader, () => null, () => null, () => null, () => null, () => null, ShlinkVersions);
+
+    wrapper = shallow(
+      <App
+        fetchServers={() => {}}
+        servers={{}}
+        settings={Mock.all<Settings>()}
+        appUpdated={false}
+        resetAppUpdate={() => {}}
+      />,
+    );
+  });
+  afterEach(() => wrapper.unmount());
+
+  it('renders a header', () => expect(wrapper.find(MainHeader)).toHaveLength(1));
+
+  it('renders versions', () => expect(wrapper.find(ShlinkVersions)).toHaveLength(1));
+
+  it('renders an update banner', () => expect(wrapper.find(AppUpdateBanner)).toHaveLength(1));
+
+  it('renders app main routes', () => {
+    const routes = wrapper.find(Route);
+    const expectedPaths = [
+      '/',
+      '/settings',
+      '/server/create',
+      '/server/:serverId/edit',
+      '/server/:serverId',
+    ];
+
+    expect.assertions(expectedPaths.length + 1);
+    expect(routes).toHaveLength(expectedPaths.length + 1);
+    expectedPaths.forEach((path, index) => {
+      expect(routes.at(index).prop('path')).toEqual(path);
+    });
+  });
+});