Jest is a popular JavaScript testing framework, and it's the default choice for most React projects.
It is known for being fast, feature-rich, and easy to set up.

How Jest works with React:

• Test runner: Jest finds and runs your test files automatically.
• Assertions: You can use built-in functions like expect() to check whether your component outputs or behaviors are correct.
• Mocking: Jest lets you mock modules, API calls, and functions, so you can test components in isolation.
• Snapshot testing: You can generate UI snapshots to detect unexpected UI changes.
• Built-in coverage reports: Jest can measure how much of your code is covered by tests without extra setup.

Example (simple React test with Jest):

import { render } from '@testing-library/react';
import App from './App';

test('renders welcome message', () => {
  const { getByText } = render(<App />);
  expect(getByText(/welcome to my app/i)).toBeInTheDocument();
});

Jest is tightly integrated with tools like React Testing Library to offer a complete testing experience.

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