Express.JS 4 generator with Socket.io (Modified files to make this work)

app.js

var createError = require('http-errors');
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var logger = require('morgan');
var sassMiddleware = require('node-sass-middleware');

var indexRouter = require('./routes/index');
var usersRouter = require('./routes/users');

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

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'pug');

app.use(function (req, res, next) {
    res.io = io;
    next();
});
app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({extended: false}));
app.use(cookieParser());
app.use(sassMiddleware({
    src: path.join(__dirname, 'public'),
    dest: path.join(__dirname, 'public'),
    indentedSyntax: true, // true = .sass and false = .scss
    sourceMap: true
}));
app.use(express.static(path.join(__dirname, 'public')));

app.use('/', indexRouter);
app.use('/users', usersRouter);

// catch 404 and forward to error handler
app.use(function (req, res, next) {
    next(createError(404));
});

// error handler
app.use(function (err, req, res, next) {
    // set locals, only providing error in development
    res.locals.message = err.message;
    res.locals.error = req.app.get('env') === 'development' ? err : {};

    // render the error page
    res.status(err.status || 500);
    res.render('error');
});

module.exports = {
    app: app,
    server: server
};

index.pug

extends layout

block content
    h1= title
    p Welcome to #{title}
    script(src="/socket.io/socket.io.js")
    script.
        var socket = io('//localhost:3000');
        socket.on('socketToMe', function (data) {
            console.log(data);
        });

users.js

var express = require('express');
var router = express.Router();

/* GET users listing. */
router.get('/', function (req, res, next) {
    res.io.emit("socketToMe", "users");
    res.send('respond with a resource');
});

module.exports = router;

www

#!/usr/bin/env node

/**
 * Module dependencies.
 */

// var app = require('../app');
var app = require('../app').app;
var debug = require('debug')('heed:server');
var http = require('http');

/**
 * Get port from environment and store in Express.
 */

var port = normalizePort(process.env.PORT || '3000');
app.set('port', port);

/**
 * Create HTTP server.
 */
// var server = http.createServer(app);
var server = require('../app').server;

/**
 * Listen on provided port, on all network interfaces.
 */

server.listen(port);
server.on('error', onError);
server.on('listening', onListening);

/**
 * Normalize a port into a number, string, or false.
 */

function normalizePort(val) {
  var port = parseInt(val, 10);

  if (isNaN(port)) {
    // named pipe
    return val;
  }

  if (port >= 0) {
    // port number
    return port;
  }

  return false;
}

/**
 * Event listener for HTTP server "error" event.
 */

function onError(error) {
  if (error.syscall !== 'listen') {
    throw error;
  }

  var bind = typeof port === 'string'
    ? 'Pipe ' + port
    : 'Port ' + port;

  // handle specific listen errors with friendly messages
  switch (error.code) {
    case 'EACCES':
      console.error(bind + ' requires elevated privileges');
      process.exit(1);
      break;
    case 'EADDRINUSE':
      console.error(bind + ' is already in use');
      process.exit(1);
      break;
    default:
      throw error;
  }
}

/**
 * Event listener for HTTP server "listening" event.
 */

function onListening() {
  var addr = server.address();
  var bind = typeof addr === 'string'
    ? 'pipe ' + addr
    : 'port ' + addr.port;
  debug('Listening on ' + bind);
}