Publishing an NPM package

We're starting to get cosy with installing npm packages that other people and companies have made using the npm install <package-name> command. It would be great to start sharing our own handy little chunks of code with others!

Signup/login to the npm registry

• Check to see if you are logged in with npm whoami. If you are (your npm username is returned) continue to the next step.
• If not, npm adduser
• Update if prompted
• Check your email to login and verify your email address with the npm registry

Create a folder and git repository for your package

This step is optional but recommended

• mkdir <project-name>
• cd <project-name>
• git init
• git remote add origin <your-repo-url>

Initialise an npm package

• npm init
• Check out the resulting package.json and update as you see fit

Ours looks like this:

{
  "name": "hello-futureproof",
  "version": "1.0.0",
  "description": "futureproof npm package demo",
  "main": "index.js",
  "repository": {
    "type": "git",
    "url": "git+https://github.com/getfutureproof/fp_study_notes_publishing_npm_packages.git"
  },
  "author": "futureproof",
  "license": "ISC",
  "bugs": {
    "url": "https://github.com/getfutureproof/fp_study_notes_publishing_npm_packages/issues"
  },
  "homepage": "https://github.com/getfutureproof/fp_study_notes_publishing_npm_packages#readme"
}

Write some code!

• create a file called index.js (or something else, as long as you update "main" in your package.json)
• export a function from index.js using module.exports = <myFunction> - this is what will run when a user runs your package
  • you can write this as an anonymous function or point to a function defined elsewhere in your code

module.exports = function(name){
    return `Hello from npm, ${name}! Welcome to futureproof!`
}

• if you want to export more than one function, export an object with keys that point to the functions:

function plus(num1, num2){
    return num1 + num2
}

function minus(num1, num2){
    return num1 - num2
}

module.exports = {
    add: plus,
    subtract: minus
}

Set your version

• npm version 1.0.0

Stage, Commit & Push to GitHub

Only if you made a git repo before!

• you know how to do this!
• additionally, run git push --tags

Publish to the npm registry!

• npm publish
• That's it! Check out your handiwork at https://www.npmjs.com/package/<your-package-name>
• You can test your package in a sandbox at https://npm.runkit.com/<your-package-name>. See example here.

Share with others

Others can now install your package to their node project with npm install <your-package-name> and use as any other package!

const fp = require('hello-futureproof');

let greeting = fp('Beth')

console.log(greeting)

If you package exported an object rather than a function, use accordingly:

const calc = require('my-calc-package');

let result = calc.add(4, 2)

console.log(result)

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For more information including how to make a CLI executable package, check out the official documentation