Table Of ContentTest-Driven Java Development
Second Edition
Invoke TDD principles for end-to-end application
development
Alex Garcia
Viktor Farcic
BIRMINGHAM - MUMBAI
Test-Driven Java Development
Second Edition
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First published: August 2015
Second edition: March 2018
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Contributors
About the authors
Alex Garcia is a Software Engineer at Schibsted. He started coding in C++ but later moved
to Java. He is also interested in Groovy, Scala, and JavaScript. He is always eager to learn
new things and that is why he has also worked as a System Administrator and Full Stack
Engineer. He is a big fan of agile practices. He is always interested in learning new
languages, paradigms, and frameworks. When the computer is turned off, he likes to walk
around sunny Barcelona and play sports.
I enjoyed writing this book and I would like to thank those people who made this possible.
Thanks to the technical reviewers and staff at Packt Publishing for their valuable
contributions. Thanks Viktor for sharing this experience with me. And finally, special
thanks to my parents, my brother, and my girlfriend for being there whenever I need them.
Viktor Farcic is a Senior Consultant at CloudBees, a member of the Docker Captains group,
and an author. His big passions are DevOps; microservices; continuous integration,
delivery, and deployment; and test-driven development.
He often speaks at community gatherings and conferences. He published The DevOps
Toolkit series and the Test-Driven Java Development book. His random thoughts and tutorials
can be found at his blog, Technology Conversations.
I would like to thank a lot of people who have supported me during the writing of this book.
The people at Everis and Defe (companies I worked with earlier) provided all the support
and encouragement I needed. The technical reviewers, Alvaro Garcia, Esko Luontola, Jeff
Deskins, and Muhammad Ali, did a great job by constantly challenging my views, my
assumptions, and the quality of the code featured throughout the examples. Alvaro
provided even more help by writing the Legacy Code chapter. His experience and expertise
in the subject were an invaluable help. The Packt Publishing team was very forthcoming,
professional, and always available to provide guidance and support. Finally, I'd like to give
a special thanks to my daughter, Sara, and wife, Eva. With weekdays at my job and nights
and weekends dedicated to this book, they had to endure months without the support and
love they deserve. This book is dedicated to my girls.
About the reviewer
Jeff Deskins has been building web applications in the cloud since 2008 and enjoys using
new technologies to do what was previously impossible. He is continuously learning best
practices for creating high-performance applications.
Prior to his internet development career, Jeff worked for 13 years as a television news
photographer. He continues to provide internet solutions for different television stations.
I would like to thank my wife for her support and patience through the many hours of me
sitting behind my laptop learning new technologies. Love you the most!
Packt is searching for authors like you
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Table of Contents
Preface 1
Chapter 1: Why Should I Care for Test-Driven Development? 6
Why TDD? 7
Understanding TDD 8
Red-Green-Refactor 8
Speed is the key 10
It's not about testing 11
Testing 11
Black-box testing 11
White-box testing 12
The difference between quality checking and quality assurance 13
Better tests 14
Mocking 14
Executable documentation 15
No debugging 17
Summary 18
Chapter 2: Tools, Frameworks, and Environments 19
Git 20
Virtual machines 20
Vagrant 21
Docker 23
Build tools 24
The integrated development environment 26
The IDEA demo project 27
Unit-testing frameworks 28
JUnit 29
TestNG 31
Hamcrest and AssertJ 33
Hamcrest 34
AssertJ 35
Table of Contents
Code coverage tools 36
JaCoCo 36
Mocking frameworks 37
Mockito 40
EasyMock 42
Extra power for mocks 44
User interface testing 44
Web-testing frameworks 44
Selenium 45
Selenide 46
Behavior-driven development 48
JBehave 48
Cucumber 51
Summary 53
Chapter 3: Red-Green-Refactor – From Failure Through Success until
Perfection 54
Setting up the environment with Gradle and JUnit 55
Setting up Gradle/Java project in IntelliJ IDEA 55
The Red-Green-Refactor process 58
Writing a test 59
Running all the tests and confirming that the last one is failing 59
Writing the implementation code 59
Running all the tests 60
Refactoring 60
Repeating 60
Tic-Tac-Toe game requirements 61
Developing Tic-Tac-Toe 61
Requirement 1 – placing pieces 62
Test – board boundaries I 65
Implementation 66
Test – board boundaries II 66
Implementation 67
Test – occupied spot 67
Implementation 68
Refactoring 68
Requirement 2 – adding two-player support 69
[ ii ]
Table of Contents
Test – X plays first 70
Implementation 71
Test – O plays right after X 71
Implementation 71
Test – X plays right after O 72
Requirement 3 – adding winning conditions 72
Test – by default there's no winner 73
Implementation 73
Test – winning condition I 73
Implementation 74
Refactoring 74
Test – winning condition II 75
Implementation 76
Test – winning condition III 76
Implementation 77
Test – winning condition IV 77
Implementation 78
Refactoring 78
Requirement 4 – tie conditions 79
Test – handling a tie situation 79
Implementation 80
Refactoring 80
Code coverage 81
More exercises 83
Summary 83
Chapter 4: Unit Testing – Focusing on What You Do and Not on What
Has Been Done 84
Unit testing 85
What is unit testing? 85
Why unit testing? 86
Code refactoring 86
Why not use unit tests exclusively? 86
Unit testing with TDD 88
TestNG 89
The @Test annotation 89
The @BeforeSuite, @BeforeTest, @BeforeGroups, @AfterGroups,
@AfterTest, and @AfterSuite annotations 90
[ iii ]
Table of Contents
The @BeforeClass and @AfterClass annotations 91
The @BeforeMethod and @AfterMethod annotations 91
The @Test(enable = false) annotation argument 91
The @Test(expectedExceptions = SomeClass.class) annotation argument 91
TestNG versus JUnit summary 91
Remote-controlled ship requirements 92
Developing the remote-controlled ship 93
Project setup 93
Helper classes 95
Requirement – starting point and orientation 96
Specification – keeping position and direction in memory 97
Implementation 98
Refactoring 98
Requirement – forward and backward moves 99
Specification – moving forward 99
Implementation 101
Specification – moving backward 101
Implementation 102
Requirement – rotating the ship 102
Specification – turning left 102
Implementation 103
Specification – turning right 103
Implementation 103
Requirement – commands 103
Specification – single commands 104
Implementation 104
Specification – combined commands 106
Implementation 106
Requirement – representing spheric maps 107
Specification – planet information 108
Implementation 108
Refactoring 109
Specification – dealing with map boundaries 110
Implementation 110
Requirement – detecting obstacles 111
Summary 112
Chapter 5: Design – If It's Not Testable, It's Not Designed Well 113
[ iv ]
