server.js

'use strict';

const app = require('express')();
const server = require('http').Server(app);
const io = require('socket.io')(server);

const config = require('./webpack.config');
const webpack = require('webpack');
const webpackDevMiddleware = require('webpack-dev-middleware');
const webpackHotMiddleware = require('webpack-hot-middleware');

const port = process.env.PORT || 3000;

const compiler = webpack(config);
app.use(webpackDevMiddleware(compiler, {noInfo: true, publicPath: config.output.publicPath}));
app.use(webpackHotMiddleware(compiler));

app.get('/', function(req, res) {
  res.sendFile(__dirname + '/index.html');
});

io.on('connection', function (socket) {
  socket.emit('news', { hello: 'world' });
  socket.on('my other event', function (data) {
    console.log(data);
  });
});

server.listen(port, function(err) {
  if (err) {
    console.error(err);
  } else {
    console.info('Listening on port %s. Open up http://localhost:%s/ in your browser.', port, port);
  }
});