Table of Contents for
Your Code as a Crime Scene

Version ebook / Retour

Cover image for bash Cookbook, 2nd Edition Your Code as a Crime Scene by Adam Tornhill Published by Pragmatic Bookshelf, 2015
  1. Title Page
  2. Your Code as a Crime Scene
  3. Your Code as a Crime Scene
  4. For the Best Reading Experience...
  5. Table of Contents
  6. Early praise for Your Code as a Crime Scene
  7. Foreword by Michael Feathers
  8. Acknowledgments
  9. Chapter 1: Welcome!
  10. About This Book
  11. Optimize for Understanding
  12. How to Read This Book
  13. Toward a New Approach
  14. Get Your Investigative Tools
  15. Part 1: Evolving Software
  16. Chapter 2: Code as a Crime Scene
  17. Meet the Problems of Scale
  18. Get a Crash Course in Offender Profiling
  19. Profiling the Ripper
  20. Apply Geographical Offender Profiling to Code
  21. Learn from the Spatial Movement of Programmers
  22. Find Your Own Hotspots
  23. Chapter 3: Creating an Offender Profile
  24. Mining Evolutionary Data
  25. Automated Mining with Code Maat
  26. Add the Complexity Dimension
  27. Merge Complexity and Effort
  28. Limitations of the Hotspot Criteria
  29. Use Hotspots as a Guide
  30. Dig Deeper
  31. Chapter 4: Analyze Hotspots in Large-Scale Systems
  32. Analyze a Large Codebase
  33. Visualize Hotspots
  34. Explore the Visualization
  35. Study the Distribution of Hotspots
  36. Differentiate Between True Problems and False Positives
  37. Chapter 5: Judge Hotspots with the Power of Names
  38. Know the Cognitive Advantages of Good Names
  39. Investigate a Hotspot by Its Name
  40. Understand the Limitations of Heuristics
  41. Chapter 6: Calculate Complexity Trends from Your Code’s Shape
  42. Complexity by the Visual Shape of Programs
  43. Learn About the Negative Space in Code
  44. Analyze Complexity Trends in Hotspots
  45. Evaluate the Growth Patterns
  46. From Individual Hotspots to Architectures
  47. Part 2: Dissect Your Architecture
  48. Chapter 7: Treat Your Code As a Cooperative Witness
  49. Know How Your Brain Deceives You
  50. Learn the Modus Operandi of a Code Change
  51. Use Temporal Coupling to Reduce Bias
  52. Prepare to Analyze Temporal Coupling
  53. Chapter 8: Detect Architectural Decay
  54. Support Your Redesigns with Data
  55. Analyze Temporal Coupling
  56. Catch Architectural Decay
  57. React to Structural Trends
  58. Scale to System Architectures
  59. Chapter 9: Build a Safety Net for Your Architecture
  60. Know What’s in an Architecture
  61. Analyze the Evolution on a System Level
  62. Differentiate Between the Level of Tests
  63. Create a Safety Net for Your Automated Tests
  64. Know the Costs of Automation Gone Wrong
  65. Chapter 10: Use Beauty as a Guiding Principle
  66. Learn Why Attractiveness Matters
  67. Write Beautiful Code
  68. Avoid Surprises in Your Architecture
  69. Analyze Layered Architectures
  70. Find Surprising Change Patterns
  71. Expand Your Analyses
  72. Part 3: Master the Social Aspects of Code
  73. Chapter 11: Norms, Groups, and False Serial Killers
  74. Learn Why the Right People Don’t Speak Up
  75. Understand Pluralistic Ignorance
  76. Witness Groupthink in Action
  77. Discover Your Team’s Modus Operandi
  78. Mine Organizational Metrics from Code
  79. Chapter 12: Discover Organizational Metrics in Your Codebase
  80. Let’s Work in the Communication Business
  81. Find the Social Problems of Scale
  82. Measure Temporal Coupling over Organizational Boundaries
  83. Evaluate Communication Costs
  84. Take It Step by Step
  85. Chapter 13: Build a Knowledge Map of Your System
  86. Know Your Knowledge Distribution
  87. Grow Your Mental Maps
  88. Investigate Knowledge in the Scala Repository
  89. Visualize Knowledge Loss
  90. Get More Details with Code Churn
  91. Chapter 14: Dive Deeper with Code Churn
  92. Cure the Disease, Not the Symptoms
  93. Discover Your Process Loss from Code
  94. Investigate the Disposal Sites of Killers and Code
  95. Predict Defects
  96. Time to Move On
  97. Chapter 15: Toward the Future
  98. Let Your Questions Guide Your Analysis
  99. Take Other Approaches
  100. Let’s Look into the Future
  101. Write to Evolve
  102. Appendix 1: Refactoring Hotspots
  103. Refactor Guided by Names
  104. Bibliography
  105. You May Be Interested In…

Let Your Questions Guide Your Analysis

The techniques in this book came about because we needed to understand large software systems. Because, let’s face it, software development is hard—we programmers need all the help we can get. Our collection of analysis and heuristics provides such support. We just need to apply it wisely. Let’s discuss how.

Start Simple and Then Elaborate as Needed

The hotspot analysis from Part I is as close as we get to a silver bullet. Sure, you’ve learned about the limitations of hotspots; you’ve seen false positives and biased data. Yet a hotspot analysis often manages to provide you with a high-level view of the codebase’s condition. A hotspot analysis is an ideal first step.

In addition to hotspot analysis, I always check temporal coupling. Start with an analysis of individual modules, as we did back in Chapter 8, Detect Architectural Decay. Look for surprising modification patterns and patterns that cross architectural boundaries.

If you know the codebase well, I also recommend that you specify its architecturally significant boundaries in a transformation file and perform an analysis on that level, as we did in Chapter 10, Use Beauty as a Guiding Principle.

When you need more supporting data, either to understand the problems or to prioritize improvements, look to supplement your results with the code churn measures we learned about in Chapter 14, Dive Deeper with Code Churn.

Finally, you need to consider the social environment where your system evolves. Let’s recap that part.

Support Collaboration

We started Part III with an overview of how we work in groups. You learned about social biases and saw how they can turn group decisions into disasters. These biases are hard to avoid, and you should keep in mind that we need to challenge them, as we saw in Challenge with Questions and Data.

In small organizations, we all know each other and how we work. But as soon as an organization grows, even for a group of seven to ten people, things change for the worse, and you need communication aids. The knowledge map that we discussed in Chapter 13, Build a Knowledge Map of Your System, is a powerful concept to guide you in such settings.

If you work with multiple teams, I recommend that you keep track of parallel work in your codebase. As you learned in Chapter 12, Discover Organizational Metrics in Your Codebase, parallel work leads to lower-quality code and more defects. When you identify modules that suffer from parallel work, you investigate them further with fractal figures, as we did in Visualize Developer Effort with Fractal Figures.

Changing the way you work will never be easy. The techniques in this book can only help you make more informed decisions that let you move closer to your team’s potential productivity.

There’s much more to be said about the social influences on software design. For example, we haven’t talked much about how our physical workplace affects our ability to code.

Joe asks:
Joe asks:
Great, So How Does the Physical Workplace Affect Our Ability to Code?

Our office space is an important determiner of job performance. As Peopleware: Productive Projects and Teams [DL99] reports, individuals in quiet working conditions are one-third more likely to deliver zero-defect work than their peers in noisy environments. And it gets worse with increased levels of noise.

Studies like this should be an alarming message to any company that depends upon the creativity and problem-solving skills of its employees. In reality, our office environment is often neglected. Many programmers, myself included, fall back on earphones and music to shield us from the noise. It’s important to understand the tradeoffs here: when we choose a soundtrack to our code, the effect varies with the task.

Music is an excellent choice when you need a distraction to help you get through a repetitive, routine task. It may get you to perform slightly better and may make the task more enjoyable in the process. On the other hand, music will hurt your performance when working on novel and cognitively demanding tasks, which include programming. However, a noisy work environment is even worse. If you have to code under noisy conditions, music is a decent alternative. Just remember to select music with the following qualities:

  1. Avoid music that affects you emotionally. Choose something that you neither strongly like nor strongly dislike.

  2. Avoid music with lyrics, because words will compete with the code for your attention.

  3. Pick white noise if you prefer it over music. White noise works well as a noise-cancellation technique, but just like music, it cannot compete with quiet working conditions.