Serve custom .js file on Express route

I have a home page for authenticated user that is served by router however this authentication is done via cookie if there is this cookie of "session" (created after user login and defined his path to root) any request other than "home" is redirected to it (home).

More accurate to serve a% custom_config file that will receive a tokem to be used by socket.io and will also show (incorporate) basic user information and I can not do it javascript for reasons of a restrictive CSP.

How could I reconcile this?

index.js

// get routes
var GetRoutes = require('./routes/GetRoutes');
app.use('/', GetRoutes);

/**
 * Store sockets auth [in memory]
 */
var memory_auth = {};

io.on('connection', function(socket){
    // pre-store
    memory_auth[socket.id] = false;
    //
    socket.on('disconnect', function(){
        // flush socket from "memory_auth"
        try{
            delete memory_auth[socket.id];
        }catch(ex){}
    });
    //
    socket.on('authenticate', function(payload){
        //
        try{
            jwt.verify(payload, process.env.TOKEN_LOGGED, function(error, data){
                if ( !error ) {
                    /**
                     * check "socket.auth" ever "socket requests in home page"
                     */
                    memory_auth[socket.id] = true;
                    // add socket to user id room [to connect all user connections]
                    socket.join(data.id);
                }
            });
        }catch(ex){
            console.log('Authentication token failed!');
        }
        //
        setTimeout(function(){
            if ( !memory_auth[socket.id] ) {
                socket.disconnect('unauthorized');
            }
        }, 1000);
    });
});

GetRoutes.js

// middleware that is specific to this router
router.use((req, res, next)=> {
    var auth_cookie = req.signedCookies['_SCD_'];
    if ( auth_cookie && req.path !== '/home' ) {
        let user = users.getSession(auth_cookie); // function to getSession
        if ( user ) {
            res.redirect('/home');
            res.end();
        } else {
            next();
        }
    } else {
        next();
    }
});

router.get('/home', (req, res, next)=> {
    var auth_cookie = req.signedCookies['_SCD_'];
    if ( auth_cookie ) {
        let user = users.getSession(auth_cookie); // function to getSession
        if ( user ) {
            let file = getFile('home'); // function to get "home.html" file
            res.send(file);
        } else {
            res.redirect('/');
        }
    } else {
        res.redirect('/');
    }
});

router.get('/home/customJavaScript.js', (req, res, next) => {
    //
    var auth_cookie = req.signedCookies['_SCD_'];
    if ( auth_cookie ) {
        let user = users.getSession(auth_cookie); // function to getSession
        if ( user ) {
            // generate auth_token
            let auth_token = jwt.sign({
                data: {
                   id: user.id
                }
            }, process.env.TOKEN_LOGGED, { issuer: 'localhost:3000', noTimestamp: true, expiresIn: 5 });
            //
            var model = getFile('homeCustomJavaScript'); // function to get "custom.js" file
            model = model.replace(/{{+[a-zA-Z0-9_]+=+[a-zA-Z0-9=:.\/@#&-]+}}/gi, function(wholeMatch){
                if ( wholeMatch ) {
                    wholeMatch = wholeMatch.replace(/{{/g, '').replace(/}}/g, '');
                    var index = wholeMatch.split('=');
                    //
                    switch(index[0]){
                        case 'basic_nf':
                            let alias = (user.alias !== '') ? user.alias : 'Anonymous';
                            let user_nf = {
                                id: user.id,
                                alias: alias,
                                avatar: user.avatar,
                                mail: user.mail
                            };
                            return JSON.stringify(user_nf, null, 4);
                        break;
                        case 'auth_token':
                            return auth_token;
                        break;
                    }
                } else {
                    return '';
                }
            });
            res.type('application/javascript')
            .send(model)
            .end();
        } else {
            res.redirect('/');
        }
    } else {
        res.redirect('/');
    }
});

home.html

<body>
    <script src="/socket.io/socket.io.js"></script>
    <script type="text/javascript" src="./home/customJavaScript.js"></script>
</body>

customJavaScript.js

 'use strict';
 var socket = io();
/**
 * send authentication to socket connections [ever]
 * this auto add authenticated socket to user id room [to all user connections]
 */
socket.emit('authenticate', '{{auth_token=auth}}');     

var basic_user_nf = {{basic_nf=basic}};