Functional Error Handling in .NET With the Result Pattern

How should you handle errors in your code?

This has been a topic of many discussions, and I want to share my opinion.

One school of thought suggests using exceptions for flow control. This is not a good approach because it makes the code harder to reason about. The caller must know the implementation details and which exceptions to handle.

Exceptions are for exceptional situations.

Today, I want to show you how to implement error handling using the Result pattern.

It’s a functional approach to error handling, making your code more expressive.

Exceptions For Flow Control

Using exceptions for flow control is an approach to implement the fail-fast principle.

As soon as you encounter an error in the code, you throw an exception — effectively terminating the method, and making the caller responsible for handling the exception.

The problem is the caller must know which exceptions to handle. And this isn’t obvious from the method signature alone.

Another common use case is throwing exceptions for validation errors.