Concurrency in C# Cookbook, 2nd Edition

Chapter 7. Testing

Testing is an essential part of software quality. Unit testing advocates have become common in recent years; it seems that you read or hear about it everywhere. Some promote test-driven development, a style of coding that ensures you have comprehensive tests when the application is complete. The benefits of unit testing on code quality and overall time to completion are well known, and yet many developers still don’t write unit tests.

I encourage you to write at least some unit tests. Start with the code in which you feel the least confidence. In my experience, unit tests have given me two main advantages:

• Better understanding of the code. You know that part of the application that works but you have no idea how? It’s always kind of in the back of your mind when the really weird bug reports come in. Writing unit tests for code you find difficult is a great way to get a clear understanding of how it works. After writing unit tests describing its behavior, the code is no longer mysterious; you end up with a set of unit tests that describe its behavior and the dependencies that code has on the rest of the code.

• Greater confidence to make changes. Sooner or later, you’ll get that feature request that requires you to change the code that scares you, and you’ll no longer be able to pretend it isn’t there (I know how that feels; I’ve been there!). It’s best to be proactive: write the unit tests for the scary code before the feature request comes in. Once your ...