Currently working on developing an e-commerce platform, both front and back-end. Using express and passport for a basic login/register system. The issue I'm facing is that every time a page with a request is accessed, a new session is created and stored in MongoDB server, resulting in multiple sessions being created as I navigate through different sections of the site.

The goal is to have sessions created ONLY after user authentication.

Below is a snippet of my code:

app.js:

import express from "express"
import mongoose from "mongoose"
import { Server } from "socket.io"
import { boxRouter } from "./routes/box.router.js"
import { productRouter } from "./routes/product.router.js"
import { cartRouter } from "./routes/cart.router.js"
import { userRouter, isLoggedIn } from "./routes/user.router.js"
import passport from "passport"
import initializePassport from "./passport.config.js"
import cors from 'cors'
import MongoStore from "connect-mongo"
import cookieParser from "cookie-parser"
import session from "express-session"

// const hostname = '0.0.0.0'
// const port = '10000'

export var app = express()
// const httpServer = app.listen(port, hostname, ()=>{ console.log("Server Up")})
const httpServer = app.listen(8080, ()=>{ console.log("Server Up")})
export const socketServer = new Server(httpServer)

app.use(cookieParser("mostsecretsecret"))
app.use(session({
    store: MongoStore.create({
        mongoUrl: 'blablabla',
        mongoOptions: {useNewUrlParser: true, useUnifiedTopology: true},
        ttl: 15
    }),
    cookie:{
        maxAge: 7 * 24 * 60 * 60 * 1000,
    },
    secret: 'mysecret',
    resave: true,
    saveUnitialized: false
}))
initializePassport()
app.use(passport.initialize())
app.use(passport.session())
app.use(cors())
app.use(express.urlencoded({extended:true}))
app.use(express.json())

app.use('/api/boxes', boxRouter)
app.use('/api/products', productRouter)
app.use('/api/carts', cartRouter)
app.use('/api/users', userRouter)

var connectionString = "blablabla"
mongoose.set('strictQuery', false)
mongoose.connect(connectionString)

socketServer.on('connection', socket=>{
    console.log("Nuevo cliente conectado.")
})

passport.config.js:

import passport from "passport";
import local from 'passport-local';
import { userModel } from './models/user.model.js'
import { createHash, isValidPassword } from "./utils.js";
import { cartManager } from "./managers/CartManager.js";

const LocalStrategy = local.Strategy
const initializePassport = ()=>{
    passport.use('register', new LocalStrategy(
        {passReqToCallback: true, usernameField: 'email'}, async(req, username, password, done)=>{
            const { first_name, last_name, email, newsletter } = req.body
            try{
                let user = await userModel.findOne({email: username})
                if(user){
                    console.log("El usuario ya existe")
                    return done(null, false)
                }

                let newCart = await cartManager.createCart()
                const newUser = {
                    first_name,
                    last_name,
                    email,
                    password: createHash(password),
                    cartId: newCart.id,
                    newsletter,
                    role: 'user'
                }
                let result = await userModel.create(newUser)
                return done(null, result)
            }catch(err){
                return done("Error al obtener el usuario: " + err)
            }
        }
    ))
    passport.use('login', new LocalStrategy(
        {usernameField: 'email'}, async(username, password, done)=>{
            try{
                const user = await userModel.findOne({email: username})
                if(!user){
                    console.log("El usuario no existe")
                    return done(null, false)
                }
                if(!isValidPassword(user,password)) return done(null, false)
                return done(null, user)
            }catch(err){
                return done(err)
            }
        }
    ))

    passport.serializeUser((user, done)=>{
        done(null, user._id)
    })
    passport.deserializeUser(async(id, done)=>{
        let user = await userModel.findById(id)
        done(null, user)
    })
}

export default initializePassport

user.router.js:

import { Router } from 'express';
import passport from 'passport';

export const userRouter = Router()

export function isLoggedIn(req, res, next){
    if(req.session.user){
        return next()
    }
    return res.status(401).send('Error de autorización.')
}

userRouter.post('/register', passport.authenticate('register', {}), async (req, res)=>{
    try {
        res.send('Success')
    } catch (error) {
        res.status(400).send({
            status: 'error',
            message: error.message
        })
    }
})

userRouter.post('/login', passport.authenticate('login', {}), async (req, res)=>{
    try {
        if(!req.user){
            return res.status(401)
        }
        req.session.user = {
            first_name: req.user.first_name,
            last_name: req.user.last_name,
            email: req.user.email,
            role: req.user.role
        }
        res.send('Success')
    } catch (error) {
        res.status(400).send({
            status: 'error',
            message: error.message
        })
    }
})

userRouter.get('/logout', (req, res)=>{
    try {
        req.session.destroy(err=>{
            if(err) res.status(500)
        })
    } catch (error) {
        res.status(400).send({
            status: 'error',
            message: error.message
        })
    }
    
})

userRouter.get('/check-login', isLoggedIn, (req, res) => {
    try {
        res.status(200).send('Usuario logueado');
    } catch (error) {
        res.status(400).send({
            status: 'error',
            message: error.message
        })
    }
});

After browsing through 3 pages, multiple sessions are created as shown in this image of my database: https://i.sstatic.net/4rki3.png