When I started learning Node.js, I realized something: it’s not just about “how to code in Node”, but about understanding how things work under the hood.
To explore that curiosity, I built my very first tiny (assignment-level) project: NanoNode — a mini clone of the Node.js CLI.
You can run:
nanonode path_to_file.js
…and it will execute the file as if you had typed:
node path_to_file.js
👉 (Check it out on npm:)
It’s simple. It’s not “useful” for anyone. But it’s cool because it helped me connect theory and practice in a way that sticks.
🌱 The Spark: Why Do Modules Even Exist?
It all started with a question:
💭 Why is there even a need for a module system in the first place?
- Without modules, everything lives in one giant file.
- Sharing and reusing code becomes painful.
- Modularity makes large systems maintainable.
That naturally led me to:
Why do we have both CommonJS and ES6 modules?
- CommonJS was Node’s solution before JavaScript had one.
- ES6 modules became JavaScript’s native standard.
Both coexist because tech evolves, but history doesn’t vanish overnight.
🔍 Chasing the Mystery of module
When I first saw module.exports, I was confused:
💭 Where does this module object even come from?
It wasn’t in my code. Who put it there?
After digging, I discovered:
-Node.js actually wraps every file in a function (the Module Wrapper).
-That’s why arguments like module, require, exports, __dirname magically exist.
-And that’s why top-level variables are local, not truly global.
Here’s a simplified skeleton of what happens every time you run a file in Node.js:
IIFE - Immediately Invoked Function Expression
(function (exports, require, module, __filename, __dirname) {
// 👇 Your code goes here
console.log("Hello World");
// By default, module.exports = {}
})( // the argument values here);
This also explained why:
- Every file can safely have its own
module.exports. -
require(path)works by- Locating the file
- Wrapping it in this function
- Executing it
- Returning
module.exports
At that point, I could mentally sketch out how require function also worked internally. Huge “aha!” moment.
🔧 What I Learned by Building NanoNode
To turn this curiosity into something real, I wrote pari.js, a script that mimics Node’s CLI. Along the way, I learned:
-
Shebang (#!/usr/bin/env node) → lets you run scripts directly, no
nodeprefix needed. - Environment variables & PATH → how your system finds executables when you type a command.
-
Executable permissions → why
chmod +x filematters. -
npm publishing → how to make a package installable globally with
npm install -g.
All from something that just… runs a file. 😅
Why This Tiny Project Matters
The project itself is tiny. But the learnings were massive:
- I now understand how Node bootstraps code under the hood.
- I practiced packaging and publishing an npm module.
- I learned the difference between local vs truly global scope in Node. -And most importantly: theory became practical because I tied it to a goal.
As Sherlock would say, these learnings are now stored in my Mind Palace 🏰.
👀 What’s Next: A Useful CLI Tool
If NanoNode was my hello-world at the systems level, then my next project is something that actually solves a real problem:
⚡ Snapi: Fast, Lightweight CLI for Testing HTTP Requests
We all use tools like Postman or Insomnia for API testing. They’re powerful, but:
- They’re heavy.
- They take time to load.
- They’re overkill if you just want to test a quick request.
So I thought: Why not build a fast, lightweight, terminal-based request tester?
Something like:
req-test GET https://api.example.com/users
And instantly see:
- Response status
- Headers
- JSON body (pretty-printed)
🎯 Why It Should Exist
Because developers often just need something fast and minimal — no UI overhead, no extra clicks, just type a command and see results.
- Lightweight compared to Postman.
- Native to the terminal workflow.
- Useful for debugging APIs on the fly.
This time, unlike NanoNode, it’s going to be actually useful. 😉
Stay tuned — that’s what my next blog post will be about!
✨ Closing Thought
Building NanoNode taught me that small projects can unlock big insights.
Sometimes you don’t need to build the next unicorn app. Even a tiny utility can push your understanding to the next level.
And next time, I’ll share my journey of building Snapi — a CLI Request Tester. Trust me, you’ll actually want to use this one.
Top comments (4)
Great achievement
Thanks a lot!
Super cool! NanoNode might be tiny, but the way you explored Node’s internals is inspiring. Excited to see Snapi next that sounds like a tool I’d actually use! 👀
Glad you liked it! NanoNode was my tiny step into Node’s internals, and Snapi will be my attempt at making something you’d want to use daily. Excited to share progress soon