How to handle errors in Node.js middleware

Topic: Middleware in Express & Handling Requests/Responses Today I learned how middleware plays a key role in Express.js. It acts as a bridge between the client request and the server response. 🔹 Key Learnings: ✅ Middleware types → Application-level, Router-level, Built-in, Third-party ✅ Importance of order (request flows step by step, next() must be called) ✅ Built-in helpers like express.json() & express.urlencoded() ✅ Error-handling middleware → (err, req, res, next) ✅ Handling Requests: req.query, req.params, req.body, req.headers ✅ Handling Responses: res.send(), res.json(), res.status(), res.redirect() 💡 Example: Logging each request with custom middleware Handling JSON input from client Sending proper status codes & error responses This gave me a deeper understanding of how Express.js works internally and how every request passes through a series of middleware before reaching the final response. #ExpressJS #NodeJS #MERNStack #WebDevelopment #FullStackDeveloper

Understanding Middleware in Express.js 🧩 While diving deeper into backend development with Node.js and Express.js, I recently explored one of the most powerful concepts — Middleware. In simple terms, middleware functions are like checkpoints that sit between the client request 📨 and the server response 💻. They can: Modify the request or response object Run code before sending a response Handle authentication or logging Manage errors gracefully Here’s a quick example 👇 What’s happening here: Every incoming request first passes through the custom middleware. It logs the request details. Then it calls next() to move to the next handler (in this case, / route). This pattern makes Express incredibly flexible — letting you plug in modules like body-parser, cors, morgan, or even your own custom middlewares. #NodeJS #ExpressJS #BackendDevelopment #WebDevelopment #LearningInPublic

💻 Middleware: The Backbone of Your Backend In backend development, middleware controls the flow of requests—handling auth, logging, parsing, errors, —before they reach your routes. Without it, your code would be messy and insecure. With it, your backend becomes clean, modular, and professional. #NodeJS #ExpressJS #BackendDevelopment #CodingTips

Day 126 of my Node.js and Express journey, Exploring Middleware in Express.js Today I learned about middleware, one of the most powerful concepts in Express.js. Middleware functions sit between a request and a response. They can: Log requests Parse incoming data Handle authentication Serve static files Or even end a request early A key point is that middleware functions receive three parameters: req - the request object res - the response object next - a function that passes control to the next middleware For example, logging middleware might look like this: app.use((req, res, next) => { console.log(`${req.method} ${req.url}`); next(); }); This runs on every request before the route handler, logging the method and URL. Middleware is what makes Express flexible and powerful. It allows you to add functionality to your server without cluttering your route handlers. Next, I plan to explore built-in middleware like express.json() and express.static(), and also try writing custom middleware for more advanced use cases. #NodeJS #ExpressJS #BackendDevelopment #WebDevelopment #LearningJourney

Day 127 of my Node.js and Express journey, Deep Dive into Middleware Today I explored middleware in Express.js, and it’s one of the most powerful concepts for building flexible servers. Key insights: Middleware functions sit between a request and a response. They can log requests, authenticate users, modify the request/response, or even end the request early. Every middleware function receives three arguments: req, res, and next. req - information about the incoming request res - allows the middleware to send or modify a response next() - moves control to the next middleware or route handler Order matters: middleware runs in the order it’s declared. If you put a route before a middleware, that middleware might never run for that route. Forgetting next() (without sending a response) will cause the request to hang. Example: app.use((req, res, next) => { console.log(`${req.method} ${req.url}`); next(); }); app.get("/", (req, res) => { res.send("Hello from Express!"); }); Middleware lets you add functionality cleanly without cluttering route handlers. It’s incredible how much control it gives you over request handling and server logic. #NodeJS #ExpressJS #BackendDevelopment #WebDevelopment #LearningJourney

Heads Up, Next.js Developers! 🔄 Recently, Next.js announced a major change in its architecture: Middleware is now deprecated and will be replaced by the new proxy.js convention. 🔁 This move aims to reduce confusion with Express-style middlewares and make code structure clearer, especially as Next.js operates on the Edge Runtime globally. Here’s what you need to know: - Middleware files (middleware.js) will shift to proxy.js—same features, clearer purpose - You’re advised to avoid relying on Middleware unless absolutely needed - The goal is to offer ergonomic APIs so most use-cases don’t require Middleware - Edge Runtime means logic runs at the edge, with new constraints and security considerations (including possible bypass cases) Get ready for this breaking change—refactor your authentication and routing logic per route/controller, not only in Middleware! 📌 Watch the full explanation on Chai aur Code here: https://lnkd.in/gUD3SyqD Want official docs? Check: https://lnkd.in/geiHPpGq #Nextjs #Middleware #Proxy #EdgeRuntime #WebDev

Understanding Middleware in Express.js ⚡️ In Express.js, middleware are simply functions that sit between the request and the response. They have access to: req (the request object) res (the response object) next() (a function to pass control to the next middleware) 👉 Middleware is powerful because it allows us to: Log requests Authenticate users Parse data (e.g., JSON, forms) Handle errors gracefully Apply business logic before sending a response Think of middleware as a pipeline: each piece processes the request and then either sends a response or passes it down to the next function. 🔑 Key Takeaways app.use() → attaches middleware. Order matters! Middleware runs in the order they’re defined. Middleware can be global, route-specific, or error-handling. Always call next() unless you’re sending a response. #NodeJS #ExpressJS #WebDevelopment

New Project! – JWT Authentication Implementation I’ve just completed a hands-on project implementing JWT (JSON Web Token) Authentication using Node.js and Express. This project focuses on secure user login, registration, and token-based authorization, ensuring safe API access. 🔐 Key Features: - Secure user registration and login system - JWT-based authentication & authorization - Full form and server-side validation - MVC structure for better maintainability - Passwords encrypted using bcrypt - Error handling and token expiry management 🎯 Tech Stack: Node.js | Express.js | MongoDB | JWT | bcrypt 🔗 Live Demo: https://lnkd.in/d_mAy6F9 💻 GitHub Repository: https://lnkd.in/d2KhAGj8 📽️ Here’s a quick demo of the project 👇 #NodeJS #ExpressJS #JWT #Authentication #WebDevelopment #Backend #APISecurity #MERNStack #Projects

Spent days hardening the backend of a Node.js + Oracle to‑do app. Key backend improvements: ✅Enforced ownership on todos (only creators can update/delete), ✅Improved error mapping (conflicts → 409, validation → 400), ✅Made addTodo return the created ID atomically (Oracle RETURNING) so clients can update UI without full reload. ✅Add refresh tokens (or longer-lived tokens with proper revocation). ✅Next: add tests and a connection pool for better performance. Happy to share code snippets or a short walkthrough. Tech: Node.js · Express · oracledb · JWT · Fetch API #Nodejs #JavaScript #OracleDB #APIDevelopment #WebDev #FullStack #JWT #BackendDevelopment

Node.js v25.0.0 👉🏻 Upgraded to V8 14.1 — faster performance and improved JSON handling 👉🏻 Added Web Storage API and new permission model (--allow-net) 👉🏻 Removed deprecated APIs like SlowBuffer 👉🏻 Includes breaking changes, bug fixes, and general improvements https://lnkd.in/dvzGmfrd #nodejs