content: import '@babel/polyfill';
  import express from 'express';
  import React from 'react';
  import ReactDOMServer from 'react-dom/server';
  import { StaticRouter } from 'react-router';
  import bodyParser from 'body-parser';
  import { Helmet } from 'react-helmet';
  import App from './../client/index';
  
  const app = express();
  const PORT = process.env.PORT || 4000;
  
  app.use(bodyParser.json());
  app.use(express.static('build/public'));
  
  app.get('*', (req, res) => {
    const context = {};
    const content = ReactDOMServer.renderToString(
      <StaticRouter location={req.url} context={context}>
        <App />
      </StaticRouter>
    );
  
    const helmet = Helmet.renderStatic();
    const html = `
      <html>
      <head>
        ${helmet.title.toString()}
      </head>
      <body>
        <div id="root">
          ${content}
        </div>
        <script src="client_bundle.js"></script>
      </body>
      </html>
    `;
  
    res.send(html);
  });
  
  app.listen(PORT, () => {
    console.log(`App running ${PORT}`);
  });
  