|
| 1 | +import { act, renderHook } from '@testing-library/react-hooks'; |
| 2 | +import useDebouncedValue from './useDebouncedValue'; |
| 3 | + |
| 4 | +const DEFAULT_DEBOUNCE_MS = 100; |
| 5 | +beforeEach(() => { |
| 6 | + jest.useFakeTimers(); |
| 7 | +}); |
| 8 | + |
| 9 | +afterAll(() => { |
| 10 | + jest.useRealTimers(); |
| 11 | +}); |
| 12 | + |
| 13 | +it('should return the initial value', () => { |
| 14 | + const value = 'mock value'; |
| 15 | + const { result } = renderHook(() => |
| 16 | + useDebouncedValue(value, DEFAULT_DEBOUNCE_MS) |
| 17 | + ); |
| 18 | + expect(result.current).toBe(value); |
| 19 | +}); |
| 20 | + |
| 21 | +it('should return the initial value after the debounce time has elapsed', () => { |
| 22 | + const value = 'mock value'; |
| 23 | + const { result, rerender } = renderHook(() => |
| 24 | + useDebouncedValue(value, DEFAULT_DEBOUNCE_MS) |
| 25 | + ); |
| 26 | + expect(result.current).toBe(value); |
| 27 | + expect(result.all.length).toBe(1); |
| 28 | + rerender(); |
| 29 | + act(() => { |
| 30 | + jest.advanceTimersByTime(DEFAULT_DEBOUNCE_MS); |
| 31 | + }); |
| 32 | + expect(result.current).toBe(value); |
| 33 | + expect(result.all.length).toBe(2); |
| 34 | +}); |
| 35 | + |
| 36 | +it('should return the updated value after the debounce time has elapsed', () => { |
| 37 | + const value = 'mock value'; |
| 38 | + const newValue = 'mock new value'; |
| 39 | + const { result, rerender } = renderHook((val = value) => |
| 40 | + useDebouncedValue(val, DEFAULT_DEBOUNCE_MS) |
| 41 | + ); |
| 42 | + expect(result.current).toBe(value); |
| 43 | + rerender(newValue); |
| 44 | + act(() => { |
| 45 | + jest.advanceTimersByTime(DEFAULT_DEBOUNCE_MS); |
| 46 | + }); |
| 47 | + expect(result.current).toBe(newValue); |
| 48 | +}); |
| 49 | + |
| 50 | +it('should not return an intermediate value if the debounce time has not elapsed', () => { |
| 51 | + const value = 'mock value'; |
| 52 | + const intermediateValue = 'mock intermediate value'; |
| 53 | + const newValue = 'mock new value'; |
| 54 | + const { result, rerender } = renderHook((val = value) => |
| 55 | + useDebouncedValue(val, DEFAULT_DEBOUNCE_MS) |
| 56 | + ); |
| 57 | + expect(result.current).toBe(value); |
| 58 | + rerender(intermediateValue); |
| 59 | + act(() => { |
| 60 | + jest.advanceTimersByTime(DEFAULT_DEBOUNCE_MS - 5); |
| 61 | + }); |
| 62 | + expect(result.current).toBe(value); |
| 63 | + rerender(newValue); |
| 64 | + act(() => { |
| 65 | + jest.advanceTimersByTime(DEFAULT_DEBOUNCE_MS - 5); |
| 66 | + }); |
| 67 | + expect(result.current).toBe(value); |
| 68 | + act(() => { |
| 69 | + jest.advanceTimersByTime(DEFAULT_DEBOUNCE_MS); |
| 70 | + }); |
| 71 | + expect(result.current).toBe(newValue); |
| 72 | +}); |
0 commit comments