two.jsx

import React from 'react'
import { hydrate } from 'react-dom'
import { BrowserRouter as Router } from 'react-router-dom
import 'isomorphic-fetch'
import App from './App'

hydrate(
  <Router>
      <App />
  </Router>,
  document.getElementById('root')
)

if (module.hot) {
    module.hot.accept()
}