index.js

const appReducer = combineReducers({
  app,
  form: formReducer,
})

// Higher order reducer that resets the redux state when we dispatch a logout action
const rootReducer = (state, action) => {
  if (['LOGOUT'].includes(action.type)) {
    state = undefined
  }
  return appReducer(state, action)
}

export default rootReducer