server-render-like-a-pro-4.js

import createHistory from 'history/createMemoryHistory'
import configureStore from '../src/configureStore'

export default async (req, res) => {
  const history = createHistory({ initialEntries: [req.path] })
  const { store, thunk } = configureStore(history)
  
  await thunk(store) // THE PAYOFF!

  const status = store.getState().location.type === NOT_FOUND ? 404 : 200
  res.status(status)
  return store
}