We are going to create a small NPM module that will be deployed to the NPM registry.

Start off by creating a new project folder.

mkdir example-npm-module

cd example-npm-deploy

npm init -y

// add typescript and express support
npm install typescript express

// install their type definitions
npm install @types/express

// initialize a tsconfig.json file
npx tsc --init

Project Setup

Configuring the tsconfig.json file

"compilerOptions": {
  // ...
  "rootDir": "./dist", // set the root directory for the project. This is where the TSC compiler will generate the javascript files.
  "declaration": true, // generate a declaration file for the project. This is used for type checking.
  // ...
}

Configuring the package.json file

"scripts": {
  "build": "tsc", // compile the typescript files into javascript files.
}

Now if you run npm run build you will see a new folder called dist created, and a new index.js file created inside of it.

Prepping for NPM deployment Checklist

• Make sure package name is unique. Go to NPM and search for the package name. If the name is already taken, you must change the name of your project in the package.json file.
• Specify which files you want top publish to NPM. Inside of the package.json file, add the following to ensure that only the dist folder is published to NPM.

 "files": [
    "dist"
  ],

• Split your dependencies and devDependencies into two different files. Whenever you publish a package, you should only publish the dependencies. It will not install the devDependencies.

"dependencies": {
    "express": "^4.18.1"
  },
"devDependencies": {
  "typescript": "^4.7.2",
  "@types/express": "^4.17.13"
}

• Set package to be publicly accessible.

"publicConfig": {
    "access": "public"
  },

• If you are building a CLI, configure the file to run.

"bin": "dist/index.js"

Add the following to at the very top your main index.ts file in src to allow us to directly execute the file instead of writing out node dist/index.js.

#!/usr/bin/env node

• Add a prePublish script to the package.json file.

"scripts": {
  "build": "tsc",
  "prepublishOnly": "npm run build"
},

• Commit to git. Do not need to push to Github or anything like that. Just commit to git. Back in terminal, run git commit". Create a .gitignore file and add dist and node_modules to the list of files to ignore. You can confirm what files you are committing by running git status.
  • git add .
  • git commit -m "Initial commit"
• Login to NPM CLI with npm login.
• Run npm publish to publish the package to NPM.