Add client test for login and registration forms

app/client/src/App.test.js

 import React from 'react';
-import { render } from '@testing-library/react';
+import { render, waitForElement, fireEvent } from '@testing-library/react';
 import App from './App';
 
 test.skip('renders header title "ToDo App"', () => {
@@ -13,3 +13,21 @@ test('renders a header title', () => {
   const header = container.querySelector('.header-main')
   expect(header).toHaveTextContent(/.+/);
 });
+
+test('renders a login form', async () => {
+  const { getByText } = render(<App />);
+  await waitForElement(() => getByText(/Sign in/i))
+  await waitForElement(() => getByText(/Email/i))
+  await waitForElement(() => getByText(/Password/i))
+  await waitForElement(() => getByText(/Login/i))
+});
+
+test('renders registration form when register button clicked', async () => {
+  const { getByText } = render(<App />);
+  await waitForElement(() => getByText(/Signup/i))
+  fireEvent.click(getByText('Signup'))
+  await waitForElement(() => getByText(/Your name/i))
+  await waitForElement(() => getByText(/Your email/i))
+  await waitForElement(() => getByText(/Your password/i))
+  await waitForElement(() => getByText(/Create User/i))
+});