Test-driven, test-first, and test-early development practices are helping thousands of software development organizations improve their software. Now, in Quality Code: Software Testing Principles, Practices, and Patterns, Stephen Vance builds on all that’s been learned about test-driven development, helping you achieve unprecedented levels of first-time quality. Using real-world code examples, this guide introduces patterns, principles, and more than two dozen detailed techniques for testing any software system more fully, effectively, and painlessly. Vance presents a conceptual framework to help you focus your efforts and design recommendations for improving testability across the software lifecycle, and also provides hands-on guidance to simplify testing of the full spectrum of code constructs. You’ll learn how to choose the best testing techniques for every situation, from the most common scenarios to threading. Two complete case studies put it all together, walking you through testing a brand-new Java application and an untested “legacy” JavaScript jQuery plugin. Whether you’re developing cutting-edge code for a new start-up, or maintaining an unruly old system, this guide will help you deliver exactly what you need: quality code.   • Simplify unit testing of all your code—and improve integration and system testing • Delineate intent and implementation to promote more reliable and scalable testing • Overcome confusion and misunderstandings about the mechanics of writing tests • Test “side effects,” behavioral characteristics, and contextual constraints • Understand subtle interactions between design and testability—and make them work for, not against, you • Discover core principles that guide your key testing decisions • Explore testing getters/setters, string handling, encapsulation, override variations, visibility, singleton patterns, error conditions, and more • Reproduce and test complex race conditions deterministically  

Table of Contents:
Preface xiii Acknowledgments xvii About the Author xix   Part I: Principles and Practices of Testing 1   Chapter 1: Engineering, Craftsmanship, and First-Time Quality 3 Engineering and Craftsmanship 4 The Role of Craftsmanship in First-Time Quality 4 Practices Supporting Software Craftsmanship 6 Unit Testing under Code Checker Constraints 10 Unit Testing for Coverage 10   Chapter 2: Intent of Code 17 Where Did I Put That Intent? 18 Separating Intent from Implementation 18 A Simple Example That Makes You Think 19   Chapter 3: Where Do I Start? 23 An Approach to Testing 23   Chapter 4: Design and Testability 37 A Word on Design Paradigms 37 Encapsulation and Observability 38 Coupling and Testability 42   Chapter 5: Testing Principles 47 Craft Your Tests Well 47 Avoid Test Code in Production 51 Verify Intent over Implementation 52 Minimize Coupling 53 Prefer Minimal, Fresh, Transient Fixtures 54 Use Available Facilities 55 Prefer Complete over Partial Verification 55 Write Small Tests 55 Separate Your Concerns 56 Use Unique Values 57 Keep It Simple: Remove Code 58 Don’t Test the Framework 58 Sometimes Test the Framework 60   Part II: Testing and Testability Patterns 61   Chapter 6: The Basics 63 Bootstrapping Constructors 63 Testing Simple Getters and Setters 66 Share Constants 67 Locally Redefine 70 Temporarily Replace 71 Encapsulate and Override 72 Adjust Visibility 75 Verification by Injection 77   Chapter 7: String Handling 81 Verification by Containment 81 Verification by Pattern 83 Exact Verification by Value 85 Exact Verification with Formatted Results 88   Chapter 8: Encapsulation and Override Variations 91 Data Injection 91 Encapsulate Loop Conditions 94 Error Injection 96 Replace Collaborators 98 Use Existing No-Op Classes 101   Chapter 9: Adjusting Visibility 105 Packaging Tests with Code 105 Break It Down 108 Changing Access Levels 109 Test-Only Interfaces 111 Naming the Unnamed 112 Becoming friend-ly 113 Coerced Access via Reflection 114 Declarative Scope Changing 116   Chapter 10: Interlude: Revisiting Intent 119 Testing the Singleton Pattern 120 Singleton Intent 121 The Testing Strategy 121 Discerning Intent 127   Chapter 11: Error Condition Verification 129 Check the Return Value 129 Verify the Exception Type 130 Verify the Exception Message 132 Verify the Exception Payload 134 Verify the Exception Instance 137 Thoughts on Exception Design 140   Chapter 12: Use Existing Seams 145 Direct Calls 146 Dependency Injection 147 Callbacks, Observers, Listeners, and Notifiers 150 Registries 154 Factories 156 Logging and Other Facilities of Last Resort 159   Chapter 13: Parallelism 165 A Brief Introduction to Threads and Race Conditions 166 A Strategy for Race Condition Reproduction 170 Test the Thread Task Directly 173 Synchronize through Common Lock 176 Synchronize through Injection 181 Use Supervisory Control 184 Statistical Verification 187 Debugger APIs 189   Part III: Worked Examples 193   Chapter 14: Test-Driven Java 195 Bootstrapping 196 First Functionality 197 Cutting the Cord 198 Moving to Multiples 199 Ghost Protocol 200 Exercising Options 203 Moving Downstream 204 Retrospective 207   Chapter 15: Legacy JavaScript 209 Getting Started 210 DOMination 211 On Toothpaste and Testing 213 Scaling Up 215 Software Archeology 217 Retrospective 218   Bibliography 219 Index 221