Custom Error Handler Middleware

An easy-to-use custom error handler middleware for Express.js. This package provides a structured way to handle errors in your backend application, with support for custom error classes and environment-specific stack traces.

Features

• Custom Error Class: Standardize error responses with a custom error class.
• Environment-Specific Stack Traces: Includes stack traces in development mode only.
• Easy Integration: Plug-and-play error handling for Express.js.

Installation

Install the package via npm:

npm install error-handler-cli

Usage

1. Import the Middleware

const { CustomError, errorHandler } = require('error-handler-cli');

2. Create an Express Application

Here's an example of how to use the custom error handler in an Express.js app:

const express = require('express');
const { CustomError, errorHandler } = require('error-handler-cli');

const app = express();

// Route that throws a custom error
app.get('/error', (req, res, next) => {
    throw new CustomError('Invalid request data', 400);
});

// Route that throws a generic error
app.get('/generic-error', (req, res, next) => {
    next(new Error('Something went wrong!'));
});

// Use the custom error handler middleware
app.use(errorHandler);

app.listen(3000, () => {
    console.log('Server running on port 3000');
});

3. Environment-Specific Stack Traces

• Development Mode: Displays detailed error messages and stack traces.
• Production Mode: Hides stack traces for security. Set NODE_ENV=production to enable this.

API

CustomError Class

The CustomError class is used to create standardized error objects.

Constructor:

new CustomError(message, statusCode)

• message (string): The error message.
• statusCode (number): The HTTP status code (default: 500).

errorHandler Middleware

The errorHandler middleware is used to catch and process errors.

Signature:

errorHandler(err, req, res, next)

• Automatically formats and sends error responses.
• Includes stack traces in development mode.

Example Response

Development Mode

{
    "success": false,
    "message": "Invalid request data",
    "stack": "Error: Invalid request data\n    at /path/to/file.js:10:10"
}

Production Mode

{
    "success": false,
    "message": "Invalid request data"
}

Contributing

Feel free to contribute by submitting issues or pull requests. We welcome all contributions!

License

This project is licensed under the ISC License. See the LICENSE file for more details.

Author

Developed by Aashish Timsina.

https://github.com/aashish0241