1 dashboard.js

// module exports function that accepts an 'app' parameter
module.exports = function (app) {

  // routes are attached to the app as usual
  app.get("/dashboard", function (req, res) {

    if (req.session.user) {
      res.render('dashboard.ejs', {'title':'Dashboard'});
    } else {
      res.redirect('/login');
    }

  });

};

2 app.js

// main app.js example
// require route modules and pass in the app
var app = express();
require('./routes/dashboard.js')(app);
require('./routes/portal.js')(app);