React Testing Library (RTL) is a lightweight testing library designed to test React components in a way that mirrors how users interact with them.

Main principles of RTL:

• Focuses on what the user sees and does, not on the implementation details of components.
• Encourages tests that are resilient to internal changes but sensitive to real user behavior.
• Avoids using component internals like state or props directly in tests.

Key features:

• Queries like getByText, getByRole, and getByLabelText help you find elements the same way a user would.
• Simulates real user events like clicks, typing, or form submissions using @testing-library/user-event.
• Works seamlessly with Jest for a complete testing setup.

Example:

import { render, screen, fireEvent } from '@testing-library/react';
import Button from './Button';

test('calls onClick when clicked', () => {
  const handleClick = jest.fn();
  render(<Button onClick={handleClick} />);
  
  fireEvent.click(screen.getByRole('button'));
  expect(handleClick).toHaveBeenCalledTimes(1);
});

React Testing Library helps ensure your tests are user-focused, leading to better and more maintainable code.

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