NPM Scripts: Automate Your Workflow

What are NPM Scripts?

NPM scripts let you define custom commands in package.json to automate tasks like building, testing, and starting your app.

Defining Scripts

{
  "scripts": {
    "start": "node index.js",
    "dev": "nodemon index.js",
    "build": "webpack",
    "test": "jest",
    "lint": "eslint ."
  }
}

Running Them

npm start        # special — no "run" needed
npm test         # special
npm run dev      # custom scripts need "run"
npm run build

Pre & Post Hooks

{
  "scripts": {
    "prebuild": "npm run clean",  // runs before build
    "build": "webpack",
    "postbuild": "echo Done!"     // runs after build
  }
}

Chaining Scripts

"ci": "npm run lint && npm test && npm run build"

FAQs

Why "run" for some but not others?

start and test are built-in shortcuts; custom scripts need run. More in our NPM guides.

Can scripts call other scripts?

Yes — npm run other inside a script.