react testing reducer

.js

  it.only('counter COUNTER_PLUS state', () => {
    const store = global.mockStore(INITIAL_STATE)
    const actions = store.dispatch(plus(1))
    const testFn = counter(store.getState(), actions)
    expect(testFn).toEqual({
      number: 1
    })
    expect(store.getActions()[0]).toEqual({
      type: types.COUNTER_PLUS,
      payload: 1
    })
  })