Testing

import {render, screen, waitFor} from '@testing-library/react'  

Jest

Use Create-React-App
This uses both Jest and React-Testing-Library

react-scripts

automatically sets up our server to watch for changes.
If the test file is modified the server automatically compiles and reruns the test(s)

test('description', () => {  
  render(<App />); 
  const getElement = screen.getByText(/learn react/i); 
  expect(getElement).toBeInTheDocument(); 
}); 

describe(my test block',() => {  
   test('isTrue', () => {  
     render(<App />); 
     expect(true).toBe(true); 
   }); 
}); 

This will run all the tests

npm run test