Book Image

Test-Driven Java Development, Second Edition - Second Edition

By : Viktor Farcic, Alex Garcia
Book Image

Test-Driven Java Development, Second Edition - Second Edition

By: Viktor Farcic, Alex Garcia

Overview of this book

Test-driven development (TDD) is a development approach that relies on a test-first procedure that emphasizes writing a test before writing the necessary code, and then refactoring the code to optimize it.The value of performing TDD with Java, one of the longest established programming languages, is to improve the productivity of programmers and the maintainability and performance of code, and develop a deeper understanding of the language and how to employ it effectively. Starting with the basics of TDD and understanding why its adoption is beneficial, this book will take you from the first steps of TDD with Java until you are confident enough to embrace the practice in your day-to-day routine.You'll be guided through setting up tools, frameworks, and the environment you need, and we will dive right into hands-on exercises with the goal of mastering one practice, tool, or framework at a time. You'll learn about the Red-Green-Refactor procedure, how to write unit tests, and how to use them as executable documentation.With this book, you'll also discover how to design simple and easily maintainable code, work with mocks, utilize behavior-driven development, refactor old legacy code, and release a half-finished feature to production with feature toggles.You will finish this book with a deep understanding of the test-driven development methodology and the confidence to apply it to application programming with Java.
Table of Contents (18 chapters)
Title Page
Packt Upsell
Contributors
Preface
9
Refactoring Legacy Code – Making It Young Again
Index

Mocking


Everyone who has done any of the applications more complicated than Hello World knows that Java code is full of dependencies. There can be classes and methods written by other members of the team, third-party libraries, or external systems that we communicate with. Even libraries found inside JDK are dependencies. We might have a business layer that communicates with the data access layer which, in turn, uses database drivers to fetch data. When working with unit tests, we take dependencies even further and often consider all public and protected methods (even those inside the class we are working on) as dependencies that should be isolated.

When doing TDD on the unit tests level, creating specifications that contemplate all those dependencies can be so complex that the tests themselves would become bottlenecks. Their development time can increase so much that the benefits gained with TDD quickly become overshadowed by the ever-increasing cost. More importantly, those same dependencies...