Testing React 19 Components

For Vitest test structure and mocking patterns (describe/test blocks, vi.fn(), assertions), see vitest-4/skills/writing-vitest-tests/SKILL.md.

Basic Component Testing

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

test('button renders and handles click', async () => {
  const handleClick = vi.fn();

  render(<Button onClick={handleClick}>Click me</Button>);

  const button = screen.getByRole('button', { name: /click me/i });
  expect(button).toBeInTheDocument();