npm Package Manager

Comprehensive npm (Node Package Manager) commands and workflows for JavaScript and Node.js development.

Installation & Setup

Install Node.js and npm

# Using Node Version Manager (recommended)
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.0/install.sh|bash
nvm install node
nvm use node

# Direct download from nodejs.org
# Or using package managers:
# macOS: brew install node
# Ubuntu: sudo apt install nodejs npm
# Windows: choco install nodejs

Basic Package Operations

Command	Description
`npm install package_name`	Install package locally
`npm install -g package_name`	Install package globally
`npm uninstall package_name`	Uninstall package
`npm update`	Update all packages
`npm update package_name`	Update specific package
`npm list`	List installed packages
`npm list -g`	List global packages

Project Management

Project Initialization

Command	Description
`npm init`	Initialize new project
`npm init -y`	Initialize with defaults
`npm init @scope`	Initialize with scoped template
`npm create package_name`	Create project with template

Dependency Management

Command	Description
`npm install`	Install all dependencies
`npm install --save package`	Install and save to dependencies
`npm install --save-dev package`	Install and save to devDependencies
`npm install --save-optional package`	Install as optional dependency
`npm install --no-save package`	Install without saving

Package Information

Command	Description
`npm search keyword`	Search for packages
`npm info package_name`	Show package information
`npm view package_name`	View package details
`npm outdated`	Show outdated packages
`npm audit`	Check for vulnerabilities
`npm audit fix`	Fix vulnerabilities

Scripts and Execution

Script Management

Command	Description
`npm run script_name`	Run custom script
`npm start`	Run start script
`npm test`	Run test script
`npm run build`	Run build script
`npm run dev`	Run development script

Example package.json Scripts

\\\\{
  "scripts": \\\\{
    "start": "node server.js",
    "dev": "nodemon server.js",
    "build": "webpack --mode production",
    "test": "jest",
    "lint": "eslint src/",
    "format": "prettier --write src/"
  \\\\}
\\\\}

Version Management

Semantic Versioning

Command	Description
`npm version patch`	Increment patch version
`npm version minor`	Increment minor version
`npm version major`	Increment major version
`npm version prerelease`	Create prerelease version

Package Installation by Version

Command	Description
`npm install package@1.2.3`	Install specific version
`npm install package@latest`	Install latest version
`npm install package@next`	Install next/beta version
`npm install package@^1.2.0`	Install compatible version

Configuration

npm Configuration

Command	Description
`npm config list`	Show configuration
`npm config get key`	Get configuration value
`npm config set key value`	Set configuration value
`npm config delete key`	Delete configuration

Common Configuration

Setting	Description
`npm config set registry https://registry.npmjs.org/`	Set registry
`npm config set init-author-name "Your Name"`	Set default author
`npm config set init-license "MIT"`	Set default license
`npm config set save-exact true`	Save exact versions

.npmrc File

# Project .npmrc
registry=https://registry.npmjs.org/
save-exact=true
engine-strict=true
fund=false
audit-level=moderate

# Global .npmrc (~/.npmrc)
init-author-name=Your Name
init-author-email=your.email@example.com
init-license=MIT

Publishing

Package Publishing

Command	Description
`npm login`	Login to npm registry
`npm whoami`	Check logged in user
`npm publish`	Publish package
`npm publish --access public`	Publish scoped package publicly
`npm unpublish package@version`	Unpublish specific version

Publishing Workflow

# 1. Update version
npm version patch

# 2. Build package
npm run build

# 3. Test package
npm test

# 4. Publish
npm publish

# 5. Tag release
git tag v1.0.0
git push origin v1.0.0

Advanced Usage

Workspaces (npm 7+)

\\\\{
  "name": "my-monorepo",
  "workspaces": [
    "packages/*",
    "apps/*"
  ]
\\\\}

Command	Description
`npm install --workspaces`	Install all workspace dependencies
`npm run test --workspaces`	Run tests in all workspaces
`npm run build --workspace=package-a`	Run command in specific workspace

Package Linking

Command	Description
`npm link`	Create global link
`npm link package_name`	Link to global package
`npm unlink package_name`	Unlink package

Cache Management

Command	Description
`npm cache verify`	Verify cache integrity
`npm cache clean --force`	Clear cache
`npm cache ls`	List cached packages

Security

Security Auditing

Command	Description
`npm audit`	Check for vulnerabilities
`npm audit --audit-level high`	Check high severity only
`npm audit fix`	Fix vulnerabilities automatically
`npm audit fix --force`	Force fix (may break changes)

Package Verification

Command	Description
`npm pack`	Create tarball
`npm pack --dry-run`	Show what would be packed
`npm install package.tgz`	Install from tarball

Performance Optimization

Faster Installation

# Use npm ci for CI/CD
npm ci

# Parallel installation
npm install --prefer-offline

# Skip optional dependencies
npm install --no-optional

# Production only
npm install --production

Alternative Package Managers

Manager	Installation	Benefits
Yarn	`npm install -g yarn`	Faster, deterministic
pnpm	`npm install -g pnpm`	Disk space efficient
Bun	`curl -fsSL https://bun.sh/install \\|bash`	Extremely fast

Troubleshooting

Common Issues

Problem	Solution
Permission errors	Use nvm or fix permissions
Package conflicts	Delete node_modules and reinstall
Outdated npm	`npm install -g npm@latest`
Registry issues	`npm config set registry https://registry.npmjs.org/`

Debugging

Command	Description
`npm doctor`	Check npm environment
`npm ls`	Check dependency tree
`npm ls --depth=0`	Show top-level dependencies
`npm why package_name`	Show why package is installed

Reset and Clean Install

# Clean install
rm -rf node_modules package-lock.json
npm install

# Clear npm cache
npm cache clean --force

# Reset npm configuration
npm config edit

Best Practices

Package.json Management

\\\\{
  "name": "my-project",
  "version": "1.0.0",
  "description": "Project description",
  "main": "index.js",
  "engines": \\\\{
    "node": ">=16.0.0",
    "npm": ">=8.0.0"
  \\\\},
  "dependencies": \\\\{
    "express": "^4.18.0"
  \\\\},
  "devDependencies": \\\\{
    "jest": "^29.0.0",
    "eslint": "^8.0.0"
  \\\\},
  "peerDependencies": \\\\{
    "react": ">=16.0.0"
  \\\\}
\\\\}

Development Workflow

Version Pinning: Use exact versions for critical dependencies
Lock Files: Commit package-lock.json to version control
Security: Regular security audits with npm audit
Testing: Test before publishing with npm pack
Documentation: Maintain comprehensive README

Performance

CI/CD: Use npm ci in continuous integration
Caching: Leverage npm cache in CI environments
Selective Installation: Use --production for production builds
Alternative Managers: Consider yarn or pnpm for large projects
Registry: Use private registry for internal packages