Node JS App Better design and seperation

Question

I've created a node application with express. I try to separate the following layers which will give me the ability to test the application with unit testing...

The problem is that I don't know how to call to the router.js file which will stops in the post/get/delete application.

The server.js file looks as follows

http = require('http'),
app = require('./app')(),
http.createServer(app).listen(app.get('port'), function (err) {
    console.log('Express server listening on port ' + app.get('port'));
});

This is the app.js file

var express = require('express'),
logger = require('morgan'),
bodyParser = require('body-parser'),
routesApp = require('./ro/route');

module.exports = function () {
    var app = express();
    app.set('port', process.env.PORT || 3005);

    app.use(logger('dev'));
    app.use(function (req, res, next) {
        res.set('APP', 'User app');
        next();
    });
    app.use(bodyParser.json());
    app.use(routesApp);
    return app;
};

This is the router.js, which will route the call to other module according to the http type like post/delete/get etc...

var handleGet = require('../controller/handleGet');
var handlePost = require('../controller/handlePost');
var express = require('express');

    module.exports = function (app) {

        var appRoute = express.Router();
        app.use(appRoute);
        appRoute.route('*')
            .post(function (req, res) {
                handlePost(req, res);
            })
            .get(function (req, res) {
                handleGet(req, res)
            })

Currently I've two questions:

1. How to make it work since when in debug It dump in app.use(appRoute); on the router.js file? The error is TypeError: undefined is not a function

2. Is it good way to structure the node app like in my post? I want to seperate all this layers like SOC, I'm fairly new to node and express and I try to build it to be modular and testable...

Answer 1

1. How to make it work since when in debug It dump in app.use(appRoute); on the router.js file? The error is TypeError: undefined is not a function

This fails because you don't pass app into the module when you require it in app.js, you would need to do something like

app.use(routesApp(app)); // <- this hurts my eyes :(

2. Is it good way to structure the node app like in my post?I want to sperate all this leyrs like SOC,I fairly new to node and express and I try to build it to be modular and testable...

Your definitely on the right track, keeping things separated is generally always a good idea. Testing is definitely one of the big pluses but it also helps with other things like maintainability & debugging.

Personally, I would make use of the bin directory for any start up script configuration

bin/www

var app = require('./app');
app.set('port', process.env.PORT || 3005);
var server = app.listen(app.get('port'), function() {
    console.log('Express server listening on port ' + app.get('port'));
});

This will help decouple your express app from all the environment setup. This should keep your app.js clean and only contain app-related config

app.js

var express = require('express')
  , app = express()
  , logger = require('morgan')
  , bodyParser = require('body-parser')
  , routes = require('./routes.js');

app.use(logger('dev'));
app.use(function (req, res, next) {
    res.set('APP', 'User app');
    next();
});
app.use(bodyParser.json());
app.use('/', routes);
...
module.exports = app;

Then finally, your routes.js should do nothing but handle your URLs

routes.js

var express = require('express')
  , router = express.Router()
  , handleGet = require('../controller/handleGet')
  , handlePost = require('../controller/handlePost');

router.get('/', handleGet);
router.post('/', handlePost);
...
module.exports = router;