React Testing Library And Jest- The Complete Guide ✰ «UPDATED»

// Test behavior, not implementation expect(screen.getByText('Welcome John')).toBeInTheDocument()

// Use userEvent instead of fireEvent await user.click(button) React Testing Library and Jest- The Complete Guide

test('consumes context', () => const getByText = customRender(<ThemedComponent />, providerProps: initialTheme: 'dark' ) expect(getByText(/dark mode/i)).toBeInTheDocument() ) import renderHook, act from '@testing-library/react' const useCounter = (initial = 0) => const [count, setCount] = useState(initial) const increment = () => setCount(c => c + 1) return count, increment // Test behavior, not implementation expect(screen

render(<UserProfile userId=1 />)

jest.useRealTimers() // restore Controlled component const Toggle = () => const [on, setOn] = useState(false) return ( <button onClick=() => setOn(!on)> on ? 'ON' : 'OFF' </button> ) // Test behavior

import userEvent from '@testing-library/user-event' test('form submission', async () => const user = userEvent.setup() render(<LoginForm />)