Node.js – 100+ Lab Exercises (Basic, Intermediate, Advanced)

🔰 Basic Level (30+ Exercises)

Goal: Understand core Node.js features including modules, file systems, and event-driven architecture.

Introduction to Node.js

• Print “Hello from Node.js”.

• Display command-line arguments using process.argv.

• Create a simple script to add two numbers from CLI.

• Setup and run a basic package.json.

• Use npm to install and run a package.

Core Modules

• Use the fs module to read/write files.

• Create and delete files dynamically.

• Use path to join and resolve file paths.

• Log system information using the os module.

• Create a basic timer using the timers module.

Modules & Exports

• Create a reusable math utility module.

• Export and import functions between files.

• Demonstrate module caching.

• Structure code with CommonJS modules.

Events & EventEmitter

• Create and trigger custom events.

• Build a file watcher using EventEmitter.

• Use event listeners for different events.

HTTP Server Basics

• Create a basic HTTP server with http.

• Serve HTML content via res.end().

• Send dynamic responses based on URL path.

• Set appropriate headers and status codes.

🚀 Intermediate Level (40+ Exercises)

Goal: Implement REST APIs, use Express.js, and connect with databases.

Express.js Fundamentals

• Setup an Express.js server.

• Define multiple routes (GET, POST, PUT, DELETE).

• Use route parameters and query strings.

• Send JSON responses.

• Handle form data with body-parser.

Routing & Middleware

• Create global and route-specific middleware.

• Implement error-handling middleware.

• Create an authentication middleware.

• Use CORS middleware for cross-origin requests.

• Organize routers using express.Router().

File & Directory Operations

• Upload files using multer.

• Create an image gallery with uploaded files.

• Handle JSON data and save it to local files.

• Generate logs using a custom logger module.

Working with Databases

• Connect Node.js to MongoDB using Mongoose.

• Define and use MongoDB schemas.

• Perform CRUD operations (create, read, update, delete).

• Use PostgreSQL with pg for querying.

• Create REST API with database persistence.

Async Programming

• Use callbacks to manage I/O tasks.

• Rewrite logic using Promises.

• Convert Promises to async/await.

• Handle nested async operations with try/catch.

🧠 Advanced Level (40+ Exercises)

Goal: Build production-ready services with security, real-time updates, and scalability.

Advanced Express & REST APIs

• Build a complete CRUD API with route validation.

• Use Joi for input validation.

• Integrate Swagger/OpenAPI documentation.

• Use dotenv to manage environment variables.

• Implement pagination and filtering.

Authentication & Security

• Create JWT-based user authentication.

• Hash passwords with bcrypt.

• Secure routes using authentication middleware.

• Set up role-based access control.

• Sanitize input to prevent injection attacks.

WebSocket & Real-Time Apps

• Create a real-time chat app using socket.io.

• Emit and listen for socket events.

• Broadcast messages to all clients.

• Maintain a list of active users in real-time.

• Integrate WebSocket with Express server.

Package Ecosystem & Tools

• Use nodemon for auto-restarts.

• Use morgan for HTTP request logging.

• Create a CLI tool using yargs.

• Bundle code using Webpack or esbuild.

RESTful & MVC Architecture

• Organize code using Model-View-Controller pattern.

• Use services and repositories.

• Separate route, controller, and business logic.

• Implement advanced error handling using a centralized utility.

Deployment & DevOps

• Prepare app for production with pm2.

• Create a Dockerfile for containerization.

• Connect app to a remote MongoDB Atlas cluster.

• Deploy on Heroku, Vercel, or Render.

• Monitor performance with New Relic or LogRocket.

Testing & Quality Assurance

• Write unit tests using Jest.

• Create integration tests using Supertest.

• Mock database operations for isolation.

• Measure test coverage.

• Implement CI/CD pipelines using GitHub Actions.

Capstone Projects

• Blogging Platform API – CRUD articles with JWT auth.

• Real-time Chat Application – Using socket.io.

• File Upload Service – With validation and storage.

• E-commerce Backend – Product management, cart, orders.

• IoT Logger API – REST API storing sensor data with timestamps.

✅ Tech Stack

• Node.js (v18+)

• Express.js

• MongoDB / Mongoose, PostgreSQL

• Jest, Supertest

• Docker, PM2, Socket.io

• JWT, bcrypt, dotenv