Nodejs Error Middleware

Handling errors in a Rest API with Nodejs and Express application is crucial for maintaining a smooth and seamless user experience. Integrating TypeScript adds strong typing to the mix, making error handling even more efficient and reliable. Let me shared my experiencie and by using good practice code principales we can have a custom error handling mechanism in Node.js using TypeScript. This approach not only improves code maintainability but also provides clear and descriptive error messages for debugging.

First but not least, why we have or for me must implement this approach. Let me shared some thoughts find in the research.

Error handling in any application is essential for identifying bugs and improving stability. Node.js, a popular backend framework, can become complex when handling errors across multiple layers. By leveraging TypeScript's strong typing, we can manage errors more efficiently and prevent potential bugs early in the development process. Custom error handling offers the following advantages:

Enhanced readability: Custom error classes provide more descriptive error messages.
Easier debugging: A structured error handling system simplifies tracking and fixing issues.
Unified error structure: Ensures that errors have a consistent format throughout your application.

Let's go to some example to make this clear.

The fundamental purpose of this class is to inherit from the Error interface and to be able to customize our errors. Having a SRP (Single Responsibility Principle) principle.

Now you can extend this class and create for example a error custom class for NotFoundError

Create a middleware to define you custom capture error handling, of course return a better format you response.

and register middleware in root api server class. In my case i capture for all request not found error

Implementing custom error handling in Node.js with TypeScript enhances the robustness and maintainability of your application. By using custom error classes and middleware, you ensure consistent and clear error messages, making debugging and monitoring more efficient.