Guide - React Testing Library And Jest- The Complete

// Use userEvent instead of fireEvent await user.click(button)

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

import '@testing-library/jest-dom/vitest' // or 'jest-dom' Component to test ( Button.jsx ) export const Button = ( onClick, children, disabled = false ) => ( <button onClick=onClick disabled=disabled> children </button> ) Test file ( Button.test.jsx ) import render, screen from '@testing-library/react' import userEvent from '@testing-library/user-event' import Button from './Button' test('renders button with children and handles click', async () => const handleClick = jest.fn() const user = userEvent.setup() React Testing Library and Jest- The Complete Guide

// Don't use act directly (userEvent handles it) act(() => render(<Component />) )

// Test const customRender = (ui, providerProps, ...renderOptions ) => return render( <ThemeProvider ...providerProps>ui</ThemeProvider>, renderOptions ) // Use userEvent instead of fireEvent await user

if (!user) return <div>Loading...</div> return <div>user.name</div>

getBy for things that must exist, queryBy to check for absence, findBy for async. User Interactions Always use userEvent over fireEvent (it simulates full browser behavior). disabled = false ) =&gt

// Async (for elements that appear later) await screen.findByText('Loaded')

test('loads and displays user', async () => const mockUser = name: 'John Doe' fetch.mockResolvedValueOnce( json: async () => mockUser, )

test('should increment counter', () => const result = renderHook(() => useCounter(0))

const button = screen.getByRole('button') expect(button).toHaveTextContent('OFF')