npm

npm is the default package manager for Node.js and the world's largest software registry, hosting over two million packages of open-source JavaScript code.

Installation

Get the desired version for your platform, using nvm with npm at https://nodejs.org/en/download and follow the instructions.

Initialization

• npm init: If you're working on a fresh project, to use npm you need a package.json file. This file acts as the "manifest" for your project, listing your metadata and dependencies.

• npm ci: If you're working on an imported/existing project, you need to sync/install locally the required libraries listed in an existing package.json.

Package Management

• npm install <package_name>: Downloads a package and adds it to your project.
• npm update: Updates packages to the latest version allowed by your version ranges.
• npm uninstall <package>: Removes a package from your project and the package.json.

When you install a package, two major things happen in your project folder:

• The actual code for your downloaded packages lives in the node_modules folder.

WARNING

Never manually edit files in this folder. Also, add node_modules to your .gitignore file; you don't want to upload thousands of third-party files to GitHub!

• The package.json file gets automatically generated. It records the exact version of every installed package to ensure that if someone else downloads your project, they get the exact same setup you have.

Lifecycle

When you type npm run <name>, npm looks into your package.json under the "scripts" key and executes the string associated with that name.

• npm run lint: Analyze the code for syntax errors, style violations and best practice warnings

TIP

You can fix basic formatting issues automatically by running npm run lint -- --fix instead.

• npm run dev: Live preview your code
• npm run build: Turn your code into a high-performance bundle (for production)