Node.js NPM: Complete Basic to Advanced Tutorial

What is NPM?

NPM (Node Package Manager) is the default package manager for Node.js and the largest software registry in the world.

NPM responsibilities:
- Package installation
- Version management
- Dependency resolution
- Script running
- Package publishing
- Registry hosting

NPM Basics

Installation & Setup

npm --version
npm install -g npm@latest
npm config list

Start a New Project

mkdir my-project
cd my-project
npm init
npm init -y

Basic Commands

npm install lodash
npm i -D nodemon jest
npm uninstall lodash
npm update
npm list --depth=0
npm outdated
npm view express

Package.json Deep Dive

package.json is the core configuration file for metadata, scripts, dependencies, compatibility, and publishing settings.

Complete Example

{
  "name": "my-awesome-app",
  "version": "1.0.0",
  "main": "index.js",
  "scripts": {
    "start": "node index.js",
    "dev": "nodemon index.js",
    "test": "jest"
  },
  "dependencies": { "express": "^4.18.2" },
  "devDependencies": { "nodemon": "^3.0.1", "jest": "^29.7.0" },
  "engines": { "node": ">=18.0.0", "npm": ">=9.0.0" },
  "private": true
}

Installing Packages

# Local
npm install express
# Global
npm install -g nodemon
# Dev dependency
npm install -D jest
# Production only
npm install --production
# Exact version
npm install -E express
# Specific version/tag
npm install express@4.18.2
npm install express@latest

Install Patterns

npm install
npm ci
npm install --dry-run
npm install --force

Managing Dependencies

Dependency Types

{
  "dependencies": {},
  "devDependencies": {},
  "peerDependencies": {},
  "optionalDependencies": {}
}

Commands

npm list --depth=0
npm outdated
npm update
npm uninstall express
npm dedupe
npm ci

NPM Scripts

{
  "scripts": {
    "start": "node index.js",
    "dev": "nodemon index.js",
    "test": "jest",
    "build": "webpack --mode production",
    "lint": "eslint src/"
  }
}

npm start
npm run dev
npm run test -- --coverage

Hooks

{
  "scripts": {
    "pretest": "npm run lint",
    "test": "jest",
    "posttest": "npm run coverage"
  }
}

Semantic Versioning

MAJOR.MINOR.PATCH
4.18.2
| |  +-- patch fixes
| +----- minor features (backward compatible)
+------- major breaking changes

npm version patch
npm version minor
npm version major
npm view express version

Advanced NPM Features

Workspaces

{
  "private": true,
  "workspaces": ["packages/*"]
}

npm install --workspace=packages/api
npm run test --workspaces

Link, Cache, Config, Audit

npm link
npm cache verify
npm config list
npm audit
npm audit fix

Creating and Publishing Packages

Workflow

mkdir my-awesome-package
cd my-awesome-package
npm init
npm test
npm login
npm pack
npm publish

Version and release

npm version patch
npm publish --tag beta
npm deprecate my-package@"<1.2.0" "Security issues"

NPM Security

npm audit
npm audit fix
npm audit signatures
npm profile enable-2fa auth-and-writes

CI/CD secure npmrc

//registry.npmjs.org/:_authToken=${NPM_TOKEN}
registry=https://registry.npmjs.org/
always-auth=true

NPM Performance Optimization

npm ci
npm config set progress false
npm install --prefer-offline --no-audit --no-fund
npm dedupe
npm prune --production

Alternative manager speed comparison

NPM Alternatives

Yarn

npm install -g yarn
yarn install
yarn add express

pnpm

npm install -g pnpm
pnpm install
pnpm add express

Bun

curl -fsSL https://bun.sh/install | bash
bun install
bun add express

Practical Examples

1) Full setup scripts

{
  "scripts": {
    "setup": "npm install && npm run db:migrate && npm run db:seed",
    "dev": "concurrently \"npm run dev:backend\" \"npm run dev:frontend\"",
    "deploy": "npm run test && npm run build && node scripts/deploy.js"
  }
}

2) Custom deploy script args

// node scripts/deploy.js production 1.2.0
const args = process.argv.slice(2);
const environment = args[0] || 'staging';
const version = args[1] || 'latest';

3) CI pipeline steps

npm ci
npm run lint
npm run test
npm run build
npm publish

NPM Commands Reference

Common Options

--save / -S
--save-dev / -D
--save-exact / -E
--global / -g
--production
--no-save
--dry-run
--force
--workspace / -w

10 Interview Questions + 10 MCQs

Contextual Learning Links

• HTML Tutorial - structure and semantics for web pages
• CSS Tutorial - styling concepts used in full-stack apps
• Bootstrap Tutorial - fast responsive UI building
• JavaScript Tutorial - core language foundation for Node.js