React — React Testing with Jest

Jest is a JavaScript testing framework. React apps often use it with React Testing Library to write unit tests for components and logic.

// Example test file (App.test.js)
import { render, screen } from '@testing-library/react';
import App from './App';

test('renders hello message', () => {
  render(<App />);
  const element = screen.getByText(/hello/i);
  expect(element).toBeInTheDocument();
});