The 5 fundamental rules of a Node.js Project Structure

There are a lot of possible ways to organize a Node.js project - and each of the known methods has their ups and downs. However, according to our experience, developers always want to achieve the same things: clean code and the possibility of adding new features with ease.
In the past years at RisingStack, we had a chance to build efficient Node applications in many sizes, and we gained numerous insights regarding the dos and donts of project structuring.
We have outlined five simple guiding rules which we enforce during Node.js development. If you manage to follow them, your projects will be fine:

Rule 1 - Organize your Files Around Features, Not Roles

Imagine, that you have the following directory structure:

// DON'T
.
├── controllers
|   ├── product.js
|   └── user.js
├── models
|   ├── product.js
|   └── user.js
├── views
|   ├── product.hbs
|   └── user.hbs

The problems with this approach are:

• to understand how the product pages work, you have to open up three different directories, with lots of context switching,
• you end up writing long paths when requiring modules: require('../../controllers/user.js')

Rule 1: Organize your files around features, not roles!" via @risingstack

Instead of this, you can structure your Node.js applications around product features / pages / components. It makes understanding a lot easier:

// DO
.
├── product
|   ├── index.js
|   ├── product.js
|   └── product.hbs
├── user
|   ├── index.js
|   ├── user.js
|   └── user.hbs

Rule 2 - Don't Put Logic in index.js Files

Use these files only to export functionality, like:

// product/index.js
var product = require('./product')

module.exports = {
  create: product.create
}

Rule 3 - Place Your Test Files Next to The Implementation

Tests are not just for checking whether a module produces the expected output, they also document your modules (you will learn more on testing in the upcoming chapters). Because of this, it is easier to understand if test files are placed next to the implementation.

Rule 3: Place your test files next to the implementation." via @risingstack

Put your additional test files to a separate test folder to avoid confusion.

.
├── test
|   └── setup.spec.js
├── product
|   ├── index.js
|   ├── product.js
|   ├── product.spec.js
|   └── product.hbs
├── user
|   ├── index.js
|   ├── user.js
|   ├── user.spec.js
|   └── user.hbs

Rule 4 - Use a config Directory

To place your configuration files, use a config directory.

.
├── config
|   ├── index.js
|   └── server.js
├── product
|   ├── index.js
|   ├── product.js
|   ├── product.spec.js
|   └── product.hbs

Rule 5 - Put Your Long npm Scripts in a scripts Directory

Create a separate directory for your additional long scripts in package.json

.
├── scripts
|   ├── syncDb.sh
|   └── provision.sh
├── product
|   ├── index.js
|   ├── product.js
|   ├── product.spec.js
|   └── product.hbs

Next up

In the next chapter of Node Hero, you are going to learn how to authenticate users using Passport.js. Until the next chapter comes out, feel free to ask any questions you ran into!
UPDATE: We wrote another article about Node.js project structuring, which discusses advanced techniques as well.