Advanced Node and Express - Authentication with Socket.IO

server.js

'use strict';
require('dotenv').config();
const express = require('express');
const myDB = require('./connection');
const fccTesting = require('./freeCodeCamp/fcctesting.js');
const session = require('express-session');
const passport = require('passport');
const routes = require('./routes');
const auth = require('./auth.js');

const app = express();
const http = require('http').createServer(app);
const io = require('socket.io')(http);
const passportSocketIo = require('passport.socketio');
const cookieParser = require('cookie-parser');
const MongoStore = require('connect-mongo')(session);
const URI = process.env.MONGO_URI;
const store = new MongoStore({ url: URI });

app.set('view engine', 'pug');

fccTesting(app); //For FCC testing purposes
app.use('/public', express.static(process.cwd() + '/public'));
app.use(express.json());
app.use(express.urlencoded({ extended: true }));

app.use(session({
  secret: process.env.SESSION_SECRET,
  resave: true,
  saveUninitialized: true,
  cookie: { secure: false },
  key: 'express.sid',
  store: store
}));

app.use(passport.initialize());
app.use(passport.session());

io.use(
  passportSocketIo.authorize({
    cookieParser: cookieParser,
    key: 'express.sid',
    secret: process.env.SESSION_SECRET,
    store: store,
    success: onAuthorizeSuccess,
    fail: onAuthorizeFail
  })
);

myDB(async (client) => {
  const myDataBase = await client.db('database').collection('users');

  routes(app, myDataBase);
  auth(app, myDataBase);

  let currentUsers = 0;
  io.on('connection', (socket) => {
    ++currentUsers;
    io.emit('user count', currentUsers);
    console.log('user ' + socket.request.user.username + ' connected');

    socket.on('disconnect', () => {
      console.log('A user has disconnected');
      --currentUsers;
      io.emit('user count', currentUsers);
    });
  });
}).catch((e) => {
  app.route('/').get((req, res) => {
    res.render('pug', { title: e, message: 'Unable to login' });
  });
});

function onAuthorizeSuccess(data, accept) {
  console.log('successful connection to socket.io');

  accept(null, true);
}

function onAuthorizeFail(data, message, error, accept) {
  if (error) throw new Error(message);
  console.log('failed connection to socket.io:', message);
  accept(null, false);
}

http.listen(process.env.PORT || 3000, () => {
  console.log('Listening on port ' + process.env.PORT);
});

Thank you.