Forgetful Notes

npm (Node Package Manager)

npm (Node Package Manager) is the world’s largest software registry and the default package manager for the Node.js ecosystem. It is a command-line tool that helps developers discover, share, and manage reusable code packages (or “modules”) in their projects.

Info

npm consists of two main parts: the CLI tool for interacting with packages, and the online npm Registry where those packages are hosted. It is installed automatically with Node.js.

Core Concepts

  • package.json: Every Node.js project contains a package.json file. This file lists the project’s metadata and its dependencies—the packages from the npm registry that the project needs to run.
  • node_modules: When you install packages, npm downloads them into a node_modules folder in your project directory.
  • Semantic Versioning (SemVer): npm uses SemVer to manage package versions, allowing developers to specify version ranges and manage updates predictably.

Key Features

  • Dependency Management: Automatically installs and manages the packages your project depends on, as well as their dependencies.
  • Scripts: The scripts section of package.json allows you to define and run common project tasks (e.g., starting a server, running tests).
  • Package Publishing: Allows developers to publish their own packages to the npm Registry to share with others.

Essential Commands

# Initialize a new project (creates package.json)
npm init -y
 
# Install a package and save it as a dependency
npm install <package_name>
# Shorthand
npm i <package_name>
 
# Install a package as a development dependency (e.g., a testing tool)
npm install --save-dev <package_name>
# Shorthand
npm i -D <package_name>
 
# Install all dependencies listed in package.json
npm install
 
# Uninstall a package
npm uninstall <package_name>
 
# List installed packages
npm list
 
# Run a script defined in package.json
npm run <script_name>

npm vs. Alternatives

While npm is the standard, other package managers like PNPM and Yarn have emerged to address some of its shortcomings, often focusing on faster performance and more efficient disk space usage.

npm is a fundamental tool for modern web development. It provides the building blocks that power countless applications and simplifies the process of managing dependencies in any JavaScript project.

Graph View

Backlinks