react/components/utils-shared/__tests__/current-state.test.tsx

import React, { useEffect } from 'react'
import { mount } from 'enzyme'
import useCurrentState from '../use-current-state'
import { renderHook, act } from '@testing-library/react-hooks'

describe('UseCurrentState', () => {
  it('should work correctly', () => {
    const { result } = renderHook(() => useCurrentState(''))
    expect(result.current[0]).toEqual('')

    act(() => result.current[1]('test'))
    expect(result.current[0]).toEqual('test')
    expect(result.current[2].current).toEqual('test')
  })

  it('functional update mode should be supported', () => {
    const { result } = renderHook(() => useCurrentState(0))
    expect(result.current[0]).toEqual(0)

    act(() => result.current[1](pre => pre + 10))
    expect(result.current[0]).toEqual(10)
    expect(result.current[2].current).toEqual(10)
  })

  it('only ref should track latest value', () => {
    const Mock: React.FC<{}> = () => {
      const [state, setState, stateRef] = useCurrentState('')
      useEffect(() => {
        return () => {
          setTimeout(() => {
            expect(state).not.toEqual('test2')
            expect(stateRef.current).toEqual('test2')
          }, 0)
        }
      }, [])
      useEffect(() => {
        setState('test')
        setState('test2')
      }, [])
      return <span />
    }
    const wrapper = mount(<Mock />)
    expect(() => wrapper.unmount()).not.toThrow()
  })
})