import { renderHook } from '@testing-library/react-hooks'; import { useUpdateEffect } from '../hooks/useUpdateEffect'; describe('useUpdateEffect', () => { it('should not call effect on initial mount', () => { const effect = jest.fn(); renderHook(() => useUpdateEffect(effect, [])); expect(effect).not.toHaveBeenCalled(); }); it('should call effect on update', () => { const effect = jest.fn(); const { rerender } = renderHook(({ count }) => useUpdateEffect(effect, [count]), { initialProps: { count: 0 }, }); rerender({ count: 1 }); expect(effect).toHaveBeenCalledTimes(1); }); });