React Testing Library And Jest- The Complete Guide Apr 2026

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

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

render(<Button onClick=handleClick>Click Me</Button>) React Testing Library and Jest- The Complete Guide

expect(screen.getByText('Loading...')).toBeInTheDocument()

// Test behavior, not implementation expect(screen.getByText('Welcome John')).toBeInTheDocument() act(() =&gt; result

test('toggles state on click', async () => const user = userEvent.setup() render(<Toggle />)

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

// Don't test props passed to children expect(ChildComponent).toHaveBeenCalledWith( prop: 'value' )