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

Optional – dealing with uncertainty


Since it was created, null has been used and misused by developers innumerable times in innumerable programs. One of the common cases for null is, among others, to represent the absence of a value. That is not convenient at all; it could either represent the absence of a value or the abnormal execution of a piece of code.

Moreover, in order to access variables that can potentially be null, and mitigate undesired runtime exceptions like NullPointerException, developers tend to wrap variables with an if statement so those variables are accessed in safe mode. Although it works, this protection against nulls adds some boilerplate that has nothing to do with the functionality or the goal of the code:

if (name != null) {
  // do something with name
}

The preceding code overcomes the problems that the creator of null spotted in his famous quote during a conference in 2009:

"I call it my billion-dollar mistake. It was the invention of the null reference in 1965. At...