@cc-heart/utils/__test__/src/hooks/useDebounce.test.ts

🔧 javascript common tools collection

import { useDebounce } from '../../../hooks'

describe('useDebounce', () => {
  beforeAll(() => {
    jest.useFakeTimers()
  })

  it('should be called only once when ', () => {
    const fn = jest.fn()
    const debounce = useDebounce(fn)
    debounce()
    debounce()
    debounce()
    jest.runAllTimers()
    expect(fn.mock.calls.length).toBe(1)
    expect(fn).toHaveBeenCalledTimes(1)
  })

  it('should be called every when execution is delayed', async () => {
    const fn = jest.fn()
    const debounce = useDebounce(fn, 500)
    debounce()
    jest.runAllTimers()
    debounce()
    jest.runAllTimers()
    debounce()
    jest.runAllTimers()
    expect(fn.mock.calls.length).toBe(3)
    expect(fn).toHaveBeenCalledTimes(3)
  })
})