packages/hooks/usePrevious.test.ts

   1 import { renderHook } from '@testing-library/react-hooks';
   2
   3 import usePrevious from './usePrevious';
   4
   5 describe('usePrevious()', () => {
   6     it('remembers the value passed to it in the previous render cycle', () => {
   7         const hook = renderHook(({ initial }) => usePrevious(initial), { initialProps: { initial: 0 } });
   8
   9         hook.rerender({ initial: 1 });
  10
  11         const previous = hook.result.current;
  12
  13         expect(previous).toBe(0);
  14     });
  15 });