Most developers recognize the value of unit testing—the independent testing of individual chunks, units, of code by the developer while an application is being written. Unit testing leads to easier maintenance, troubleshooting, refactoring, and integration testing of the application. To facilitate unit testing, the developer uses unit-testing frameworks such as NUnit along with various helper frameworks for more advanced testing of interaction between objects—often called "Mock Object frameworks."

Because there are few clear and defined ways on how to write unit tests well, many shops try to implement unit tests on their code, realizing too late that the tests hinder the coding cycle more than they help. This book will help you avoid mistakes when writing unit tests, and show you how to do it right—from the beginning steps to the most advanced techniques.

The Art of Unit Testing guides the reader on the journey from beginner to master in the subtle art of unit testing. Based on expert author Roy Osherove's real-world development experiences, this book shows developers how to make sure the code that they write actually works as expected, and how to make these verifications as automated as possible. Not only that, the book shows techniques that help to make sure that the tests are maintainable, readable, and test the right thing over time, avoiding the "throw-away tests" phenomenon that plagues many shops that try to write unit tests without clear guidelines. In this way it helps you make your development process—and your business—more agile.

The Art of Unit Testing starts out with the basics of how to write unit tests, what makes a good unit test, and how to avoid the pitfalls you may encounter when you try to write unit tests. You'll learn to build tests that are readable, accurate, and maintainable. Along the way, you'll pick up a set of best practices and how-tos for key subjects, from using test frameworks to using Mock Objects to writing tests that run against a database.

The author establishes rules for good unit tests built upon the three major principles that any good test be maintainable, trustworthy, and readable. You'll find clear sections presenting established best practices to ensure that your tests will adhere to these principles. The book also provides clear guidance on what to test and where to start testing when you're going into a legacy code project.

Unlike other books on this topic, this book trades theory for real-world examples. It's designed so that you, a working developer, can start writing better unit tests now.