passport.js "Cannot read property 'isAuthenticated' of undefined"

[Robert Balu]

I've read this answer and applied the solution but still not working  https://stackoverflow.com/questions/29838952/how-to-fix-typeerror-cannot-read-property-authenticate-of-undefined-passportj

routes.js 

1. module.exports = function(app, passport) {
2. .......
3. };
5. // route middleware to ensure user is logged in
6. function isLoggedIn(req, res, next) {
7.    if (req.isAuthenticated()){
8.        return next();
9.    }
10.    else{
11.      alert("not authernticated");
12.    }
13.    res.redirect('/');
14. }

server.js 

1. var express  = require('express');
2. var app      = express();
3. var port     = process.env.PORT || 8080;
4. var mongoose = require('mongoose');
5. var passport = require('passport');
6. var flash    = require('connect-flash');
7. .......
8. require('./config/passport')(passport); // pass passport for configuration
9. .....
10. // required for passport
11. app.use(session({
12.     secret: 'ilovescotchscotchyscotchscotch', // session secret
13.     resave: true,
14.     saveUninitialized: true
15. }));
16. app.use(passport.initialize());
17. app.use(passport.session()); // persistent login sessions
18. app.use(flash()); // use connect-flash for flash messages stored in session
19.  
20. // routes ======================================================================
21. require('./app/routes.js')(app, passport); // load our routes and pass in our app and fully configured passport