Catch Express Errors 🚀

Catch Express Errors is a lightweight package that provides error handling and async error catching for your Express applications. It helps you handle application errors gracefully and ensures that no errors go unnoticed.

Installation

Install the package using npm:

1npm install catch-express-error

Features

✅ Global error handler for Express
✅ Catch async function errors
✅ Custom AppError class for consistent error handling
✅ Supports both TypeScript and JavaScript
✅ Compatible with CommonJS and ES modules
✅ Easily integrate with existing Express applications
✅ Lightweight and minimalistic

Usage:

AppError

Description: AppError is a custom error class designed to represent application-specific errors. It extends the built-in Error class and allows you to create instances of errors with customized properties.

Parameters:

1. message (string): A descriptive message explaining the error.
2. statusCode (number, optional): The HTTP status code associated with the error. Defaults to 400 (Bad Request) if not provided.
3. details (any, optional): Additional details or data related to the error.
4. name (string, optional): A custom name for the error. Defaults to "App Error" if not provided.
5. code (string | number, optional): A custom error code or identifier.

catchAsync

Description: catchAsync is a higher-order function that wraps an asynchronous function to catch any errors it may throw and pass them to Express.js's error handling middleware.

Parameters:

1. fn (Function): The asynchronous function to be wrapped. It should accept (req, res, next) parameters.

handleGlobalErrors

Description: handleGlobalErrors is an Express.js error handling middleware that centralizes error handling for your application. It handles different types of errors and provides appropriate responses, including logging.

Parameters:

1. logger (Logger | null, optional): An optional Winston logger instance for logging errors. If not provided or set to null, errors will be logged to the console.
2. isProduction (boolean, optional): A flag indicating whether the application is in production mode. Defaults to false if not provided.

Please note that AppError is a class, and catchAsync and handleGlobalErrors are functions that can be used as middleware in your Express.js application to handle errors in a standardized way.

Examples:

Global Error Handler

In your app.ts or app.js file:

1import express from "express";
2import { handleGlobalErrors, AppError } from "catch-express-error";
3
4const app = express();
5
6// ...
7
8// ... Your Express routes and middleware
9
10app.use(handleGlobalErrors()); 
11
12// ...

You can also use a logger with the global error handler:

1import { handleGlobalErrors} from "catch-express-error";
2
3import { createLogger } from "winston";
4
5const logger = createLogger({
6  // configure your logger
7});
8
9const app = express();
10
11// ... Your Express routes and middleware
12
13app.use(handleGlobalErrors(logger));

Production and Development mode with and without logger.:

1import { handleGlobalErrors} from "catch-express-error";
2import { createLogger } from "winston";
3
4const logger = createLogger({
5  // configure your logger
6});
7
8const app = express();
9
10// ... Your Express routes and middleware
11
12app.use(handleGlobalErrors()); // Without 'logger' and 'development' mode
13
14app.use(handleGlobalErrors(logger)); // With 'logger' and 'development' mode.
15
16app.use(handleGlobalErrors(null, true)); // Without 'logger' and 'production' mode.
17
18app.use(handleGlobalErrors(logger, true)); // With 'logger' and 'production' mode.
19

Catch Async Function Errors

Wrap your async route handler functions using the catchAsync function to catch any errors and pass them to the global error handler:

1const { catchAsync } = require("catch-express-error");
2
3app.get(
4  "/users",
5  catchAsync(async (req, res) => {
6    // Your async code here
7  })
8);

Or

1import { catchAsync, AppError } from "catch-express-error";
2
3const signUp = catchAsync(async (req, res, next) => {
4  // Your async code here
5  if (err) return next(new AppError("Invalid authentication", 401)); // AppError example
6});
7
8// ...

AppError

Use the AppError class to create custom errors with consistent properties:

1const { AppError } = require("catch-express-error");
2
3const getUserData = async () => {
4  if (!data) throw new AppError("User not found!", 404);
5};

or

1import { AppError } from "catch-express-error";
2
3// Example usage
4return next(new AppError("Please login again", 401));

License

This package is licensed under the MIT License. See the LICENSE file for more information.

Contributing

Contributions are welcome! Feel free to open issues and submit pull requests to improve this package.

Support

If you have any questions, suggestions, or need assistance, please feel free to contact the package maintainer or open an issue on the GitHub repository.