express-project-09-global-error-handler

A simple Express.js backend project that demonstrates centralized error handling using a global error middleware.

Project Goal

This project is built to understand how global error handling works in Express.js.

It focuses on:

• creating routes and controllers
• throwing errors from a controller
• forwarding errors using next(error)
• handling all errors from one central middleware
• returning structured JSON error responses

Tech Stack

• Node.js
• Express.js
• Nodemon

Project Structure

express-project-09-global-error-handler
│
├─ src
│  ├─ controllers
│  │  └─ error.controller.js
│  │
│  ├─ routes
│  │  └─ error.route.js
│  │
│  └─ middleware
│     └─ error.middleware.js
│
├─ index.js
├─ api-test.rest
├─ .gitignore
├─ package.json
├─ package-lock.json
└─ README.md

Installation

Clone the repository:

git clone https://github.com/a2rp/express-project-09-global-error-handler.git
cd express-project-09-global-error-handler

Install dependencies:

npm install

Run the Project

Development mode with nodemon:

npm run dev

Production mode:

npm start

Server runs at:

http://localhost:1198

API Endpoints

GET /

Returns a success response.

{
    "success": true,
    "message": "Global Error Handler API is running"
}

GET /error

Throws a forced error from the controller and handles it through the global error middleware.

{
    "success": false,
    "message": "This is a forced error from the controller"
}

Learning Outcome

By building this project, you learn how to:

• separate routes, controllers, and middleware
• create a centralized error handler
• pass errors using next(error)
• keep controller code clean
• send consistent error responses

Testing

This project includes an api-test.rest file for quick API testing inside VS Code using the REST Client extension.

Author

Ashish Ranjan

Follow me

• GitHub: https://github.com/a2rp
• Portfolio: https://www.ashishranjan.net
• LinkedIn: https://www.linkedin.com/in/aashishranjan
• Facebook: https://www.facebook.com/theash.ashish/