How to Build and Publish a Custom Node.js Utility Package

🚀 View GitHub Repo: node-custom-package-guide

💡 Want to reuse common string operations like capitalize() or slugify() across projects? Learn how to create and publish your own Node.js utility package!

📁 Project Structure

custom-package/
├── index.js
├── package.json
├── README.md
└── utils/
    ├── capitalize.js
    ├── camelCase.js
    ├── slugify.js
    └── greeting.js

✅ Initialize the Package

npm init -y

This creates a package.json with default values.

🧩 Write Utility Functions

utils/capitalize.js

function capitalize(str) {
  return str.charAt(0).toUpperCase() + str.slice(1);
}
module.exports = capitalize;

utils/camelCase.js

function camelCase(str) {
  return str
    .replace(/\s(.)/g, (match, group1) => group1.toUpperCase())
    .replace(/\s/g, '')
    .replace(/^(.)/, (match, group1) => group1.toLowerCase());
}
module.exports = camelCase;

utils/slugify.js

function slugify(str) {
  return str
    .toLowerCase()
    .replace(/[^\w\s-]/g, '')
    .trim()
    .replace(/[\s_-]+/g, '-');
}
module.exports = slugify;

utils/greeting.js

function sayHello(name) {
  return `Hello, ${name}!`;
}
module.exports = sayHello;

🧩 Create the Package Entry Point

index.js

const capitalize = require('./utils/capitalize');
const camelCase = require('./utils/camelCase');
const slugify = require('./utils/slugify');
const sayHello = require('./utils/greeting');

module.exports = {
  capitalize,
  camelCase,
  slugify,
  sayHello
};

🧪 Test Your Package Locally

Step 1: Link your package globally

npm link

Step 2: Create a test project

mkdir test-custom-package
cd test-custom-package
npm init -y

Step 3: Link your custom package

npm link custom-package

Step 4: Write a test file

// index.js
const utils = require('custom-package');

console.log(utils.sayHello('Rana'));                   // Hello, Rana!
console.log(utils.capitalize('world'));                // World
console.log(utils.camelCase('hello world app'));       // helloWorldApp
console.log(utils.slugify('Node.js String Utils'));    // node-js-string-utils

Step 5: Run the file

node index.js

🚀 Optional: Publish to npm

1. Login to npm

npm login

2. Rename your package (if needed)

Use a unique name or scoped name like @yourname/custom-package.

3. Publish it

npm publish --access public

🎯 Final Thoughts

Creating a custom utility package in Node.js is a practical way to:

• Promote code reuse
• Practice modular architecture
• Contribute to open-source
• Impress recruiters or collaborators

Tip: Even simple utilities can add real value when published thoughtfully.

🌐 View Full Code on GitHub