• npm = Node Package Manager
  • Let’s you install and manage your modules. A module is just a bunch of code grouped together.
  • It makes it easy to update your modules (versions) without having to edit code.

why NPM?

  • makes it easy to download different modules
  • makes it easy to upgrade different modules (e.g. jquery, bootstrap)
  • makes it easy to remove modules
  • it’s a package manager. it makes your life easy by making managing your modules and packages easier
  • it let’s you install modules with single commands instead of having to download code locally and including it, or including links to CDNs.

getting started

npm comes with Node.js. If you have Node installed, you have npm installed. You can check if it’s already installed with

node -v
npm -v
  • install npm:
# Install on Ubuntu Debian
sudo apt update && sudo apt install nodejs npm -y
  • initialize:
npm init

inside your project folder. will create package.json

  • install modules:
npm i -S jquery
npm i -D react react-dom
  • i is short for install
  • --save or -S adds it to package.json as a dependency
  • --save-dev or -D adds it as a dev dependency.
  • Without -S or -D, jQuery would have been installed into our node_modules/ folder but not saved to the package.json file.

installing specified dependencies in package.json

if you were collaborating with a teammate, instead of having to push your entire node_modules folder to github, your teammate can just clone your project and run npm install and all of your dependencies that are saved inside of your package.json file (in this case just jquery) will be downloaded to her node_modules folder.

NPM Scripts

let’s you run commands you saved under scripts in package.json.

Inside of your package.json file, under the "scripts" property, add

"test": "ava 'app/**/*.test.js' --verbose --require ./other/setup-ava-tests.js"

so that your complete scripts sections looks like

  "scripts": {
    "test": "ava 'app/**/*.test.js' --verbose --require ./other/setup-ava-tests.js"