http2-express-push.js

const spdy = require('spdy');
const express = require('express');
const fs = require('fs');
const path = require('path');

const app = express();
const publicPath = path.join(__dirname, ".");

app.use(express.static(publicPath));

app.get('/push', (req, res) => {

  if (res.push) {

    let stream = res.push('/main.js', {
      req: {'accept': '**/*'},
      res: {'content-type': 'application/javascript'}
    });
    stream.on('error', err => {
      console.log(err);
    });
    stream.end('console.log("Success!")');

  }

  res.end("<script src='/main.js' />");

});

spdy.createServer({
  key: fs.readFileSync('./server.key'),
  cert: fs.readFileSync('./server.crt'),
  passphrase: 'password'
}, app)
  .listen(8000, (err) => {
    if (err) {
      throw new Error(err);
    }
    console.log('Listening on port:  8000.');
  });