and index.jsx tests

__tests__/index.test.jsx

@@ -0,0 +1,22 @@
+import React from 'react';
+import ReactDOM from 'react-dom';
+
+import api from '../src/api';
+
+import indexToRender from '../src/index';
+
+const custom_logo = (<div>logo</div>);
+const custom_login_info = 'custom login info';
+
+jest.mock('react-dom', () => ({ render: jest.fn() }));
+
+describe('index.jsx', () => {
+  test('renders without crashing', async () => {
+    api.getRoot = jest.fn().mockImplementation(() => Promise
+      .resolve({ data: { custom_logo, custom_login_info } }));
+
+    await indexToRender();
+
+    expect(ReactDOM.render).toHaveBeenCalled();
+  });
+});