What is React Testing Library and how does its approach to testing differ from testing internal implementation details?

React Testing Library encourages testing a component the way an actual user would interact with it, such as finding a button by its visible text and clicking it, rather than checking internal details like a component's specific state values. This makes tests more reliable, since they keep passing even if the internal code changes, as long as the actual user experience stays the same.

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

test('button increments count when clicked', () => {
  render(<Counter />);
  const button = screen.getByText('Count: 0');
  fireEvent.click(button);
  expect(screen.getByText('Count: 1')).toBeInTheDocument();
});