As a web beginner, I have implemented a sign-in feature that saves the email entered as a cookie, and an account page that deletes it when the log-out button is pressed. I am attempting to create a middleware that redirects the user to sign-in when the cookie is deleted from logging out. The sign-in route script is shown below where if the email cookie is detected, the user is redirected to the main page; otherwise, the sign-in page is rendered.

const fs = require('fs');
const path = require('path');
const { v4 } = require('uuid');
const express = require("express");
const cookieParser = require('cookie-parser'); 

const { containsObject, getUsers } = require('../Auth/auth.cjs');
const {userExists} = require('./signin.cjs')

const router = express.Router();

router.get('/', (req, res) => {

    const {cookies} = req;

    if(cookies['email']){
        res.redirect('/main');
    }
    else{
        res.render('SignIn/signin');
    }
})

router.post('/', async (req, res) => {

    const user = {
        email:req.body.email,
        password:req.body.password,
    }

    const result = await userExists(user);

    if(result){
        res.cookie('email', req.body.email);
        res.redirect('/main');
    }
    else{
        res.render('SignIn/signin', user)
    }

})

module.exports = router;

Note that the log-out button is implemented using a form:

Here is the log-out route that clears the email cookie and redirects the user to the sign-in page when the log-out button is clicked.

const fs = require('fs');
const path = require('path');
const { v4 } = require('uuid');
const express = require('express');
const { route } = require('../SignIn/signin');
const { compile } = require('ejs');

const {getUser, getPostsFromUser} = require('./account.cjs')

const router = express.Router();

router.get("/", async (req, res) => {
    const {cookies} = req;
    const email = cookies['email'];
    const userResponse = await getUser(email);

    const user = {
        username:userResponse['username'],
        email:userResponse['email'],
    }

    console.log(await getPostsFromUser(user));

    res.render('Account/account', user);
})

router.post('/', (req, res) => {

    res.cookie('email', '', {expires: new Date(0)});
    res.clearCookie("email");
    res.redirect('/sign')
})

module.exports = router;

The main file intercepts the request and response objects to check if the email cookie is defined. If it is undefined, then the client is redirected to the sign-in page. The routing implementation for the different pages are also shown below.

const { localsName } = require("ejs");
const express = require("express");
const app = express();
const cookieParser = require('cookie-parser');

const users = []
let loggedIn = false

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

app.use(cookieParser());
app.use(express.static('public'));
app.use(express.urlencoded({extended:true}))

app.use((req, res, next) => {
    const {cookies} = req;
    console.log(cookies['email'])

    if(cookies['email'] == undefined){
        return res.redirect('/sign');
    }
    else{

        next();
    }
})

app.get('/', (req, res) =>{
    res.redirect('/sign')
})

const signRouter = require('./views/SignIn/signin.js');
app.use('/sign', signRouter);

const authRouter = require('./views/Auth/auth.js');
app.use('/auth', authRouter);

const mainRouter = require('./views/Main/main.js');
app.use('/main', mainRouter);

const addPostRouter = require('./views/Addpost/addpost.js');
app.use('/add-post', addPostRouter);

const accountRouter = require('./views/Account/account.js');
app.use('/account', accountRouter);

app.listen(3000)

I have attempted multiple ways to get this to work but have been unsuccessful in rendering the sign-in page after the log-out button is clicked.