Preface

Testing with JUnit is a skill that presents much harder challenges than you might expect at first sight. This is because, despite its temptingly simple API, the tool plays ball with profound and well-conceived concepts. Hence, it's important to acquire a deep understanding of the underlying principles and practices. This avoids ending up in gridlocked development due to messed-up production and testing code.

Mastering high-quality software development driven by unit tests is about following well-attuned patterns and methods as a matter of routine rather, than reinventing the wheel on a daily basis. If you have a good perception of the conceptual requirements and a wide-ranging arsenal of solution approaches, they will empower you to continuously deliver code, which achieves excellent ratings with respect to the usual quality metrics out of the box.

To impart these capabilities, this book provides you with a well-thought-out, step-by-step tutorial. Foundations and essential techniques are elaborated, guided by a golden thread along the development demands of a practically relevant sample application. The chapters and sections are built on one another, each starting with in-depth considerations about the current topic's problem domain and concluding with an introduction to and discussion of the available solution strategies.

At the same time, it's taken care that all thoughts are backed up by illustrative images and expressive listings supplemented by adequate walkthroughs. For the best possible understanding, the complete source code of the book's example app is hosted at https://github.com/fappel/Testing-with-JUnit. This allows you to comprehend the various aspects of JUnit testing from within a more complex development context and facilitates an exchange of ideas using the repository's issue tracker.