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

act(() => result.current.increment() )

if (!user) return <div>Loading...</div> return <div>user.name</div> React Testing Library and Jest- The Complete Guide

// Wait for the user name to appear expect(await screen.findByText('John Doe')).toBeInTheDocument() const getByText = customRender(&lt

// Test const customRender = (ui, providerProps, ...renderOptions ) => return render( <ThemeProvider ...providerProps>ui</ThemeProvider>, renderOptions ) c + 1) return count

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

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