Reengineering .NET

3. Unit Testing

The primary goal of the architectural patterns we discuss is to break our application into smaller pieces that have fewer references to each other to reduce coupling. This is an advantage because it becomes much easier for a class to evolve if there are fewer hard references to it that must be updated. It also introduces more opportunities for automated testing, or unit testing.

Unit testing is a way of automating much of the quality assurance function of a development department. The goal of unit testing is to isolate classes from the rest of the application so their methods can be tested via code. We write special test methods that exercise the system under test and ensure that it executes proper logic.

Unit tests are a critical ...