Passport Login strategy and Expression Session For nodejs application created with MYSQL

nodejs-login.js

//packages used 
var session = require('express-session');
var MySQLStore = require('express-mysql-session')(session);
var passport = require('passport');
var LocalStrategy = require('passport-local').Strategy;



// express session setup and passport initialization 
var options = {

    host: 'localhost',
    user: 'root',
    password: '',
    port: 3325,
    database : 'sampleAuth'
};

var sessionStore = new MySQLStore(options);

app.use(session({
  secret: 'jhjjdddjjdhbeubvbrufbvjfjswirfiuh',
  resave: false,
  saveUninitialized: true,
  store:sessionStore
  //cookie: { secure: true }
}));

app.use(passport.initialize());
app.use(passport.session());
app.use(function(req,res,next){
  res.locals.isAuthenticated  = req.isAuthenticated();
  next();
});



// after router 
passport.use(new LocalStrategy(
  function(username, password, done) {

      const db = require('./db');

      db.query('SELECT id,password FROM user WHERE usn=?',[username],
        function(err,results,fields){
          if(err){
            done(err);
          };

          if(results.length === 0){

            done(null,false);

          }else {
            const hash = results[0].password.toString();

             bcrypt.compare(password,hash,(err,res)=>{

                if(res == true){
                    return done(null,{user_id:results[0].id});
                }else {
                  return done(null,false);
                }

            });
          }
          
      });   
  }));