Not sure why localhost isn't working

var express = require('express');
var router = express.Router();
var User = require('../models/user');
var mid = require('../middleware');

// GET /profile
router.get('/profile',mid.requiresLogin, function(req, res, next) {
  if (! req.session.userId ) {
    var err = new Error("You are not authorized to view this page.");
    err.status = 403;
    return next(err);
  }
  User.findById(req.session.userId)
      .exec(function (error, user) {
        if (error) {
          return next(error);
        } else {
          return res.render('profile', { title: 'Profile', name: user.name, favorite: user.favoriteBook });
        }
      });
});

// GET /logout
router.get('/logout', function(req, res, next) {
  if (req.session) {
    // delete session object
    req.session.destroy(function(err) {
      if(err) {
        return next(err);
      } else {
        return res.redirect('/');
      }
    });
  }
});

// GET /login
router.get('/login', mid.loggedOut, function(req, res, next) {
  return res.render('login', { title: 'Log In'});
});

// POST /login
router.post('/login', function(req, res, next) {
  if (req.body.email && req.body.password) {
    User.authenticate(req.body.email, req.body.password, function (error, user) {
      if (error || !user) {
        var err = new Error('Wrong email or password.');
        err.status = 401;
        return next(err);
      }  else {
        req.session.userId = user._id;
        return res.redirect('/profile');
      }
    });
  } else {
    var err = new Error('Email and password are required.');
    err.status = 401;
    return next(err);
  }
});

// GET /register
router.get('/register', mid.loggedOut, function(req, res, next) {
  return res.render('register', { title: 'Sign Up' });
});

// POST /register
router.post('/register', function(req, res, next) {
  if (req.body.email &&
    req.body.name &&
    req.body.favoriteBook &&
    req.body.password &&
    req.body.confirmPassword) {

      // confirm that user typed same password twice
      if (req.body.password !== req.body.confirmPassword) {
        var err = new Error('Passwords do not match.');
        err.status = 400;
        return next(err);
      }

      // create object with form input
      var userData = {
        email: req.body.email,
        name: req.body.name,
        favoriteBook: req.body.favoriteBook,
        password: req.body.password
      };

      // use schema's `create` method to insert document into Mongo
      User.create(userData, function (error, user) {
        if (error) {
          return next(error);
        } else {
          req.session.userId = user._id;
          return res.redirect('/profile');
        }
      });

    } else {
      var err = new Error('All fields required.');
      err.status = 400;
      return next(err);
    }
})

// GET /
router.get('/', function(req, res, next) {
  return res.render('index', { title: 'Home' });
});

// GET /about
router.get('/about', function(req, res, next) {
  return res.render('about', { title: 'About' });
});

// GET /contact
router.get('/contact', function(req, res, next) {
  return res.render('contact', { title: 'Contact' });
});

var express = require('express');
var bodyParser = require('body-parser');
var mongoose = require('mongoose');
var session = require('express-session');
var MongoStore = require('connect-mongo')(session);
var app = express();

// mongodb connection
mongoose.connect("mongodb://localhost:27017/bookworm");
var db = mongoose.connection;
// mongo error
db.on('error', console.error.bind(console, 'connection error:'));

// use sessions for tracking logins
app.use(session({
    secret: 'treehouse loves you',
    resave: true,
    saveUninitialized: false,
    store: new MongoStore({
        mongoooseConnection: db
    })
}));

// make user ID available in templates
app.use(function (req, res, next) {
    res.locals.currentUser = req.session.userId;
    next();
});

// parse incoming requests
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));

// serve static files from /public
app.use(express.static(__dirname + '/public'));

// view engine setup
app.set('view engine', 'pug');
app.set('views', __dirname + '/views');

// include routes
var routes = require('./routes/index');
app.use('/', routes);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('File Not Found');
  err.status = 404;
  next(err);
});

// error handler
// define as the last app.use callback
app.use(function(err, req, res, next) {
  res.status(err.status || 500);
  res.render('error', {
    message: err.message,
    error: {}
  });
});

// listen on port 3000
app.listen(3000, function () {
  console.log('Express app listening on port 3000');
});