Unit Testing Principles, Practices, and Patterns

Chapter 7. Refactoring toward valuable unit tests

This chapter covers

• Recognizing the four types of code
• Understanding the Humble Object pattern
• Writing valuable tests

In chapter 1, I defined the properties of a good unit test suite:

• It is integrated into the development cycle.
• It targets only the most important parts of your code base.
• It provides maximum value with minimum maintenance costs. To achieve this last attribute, you need to be able to:
  • Recognize a valuable test (and, by extension, a test of low value).
  • Write a valuable test.

Chapter 4 covered the topic of recognizing a valuable test using the four attributes: protection against regressions, resistance to refactoring, fast feedback, and maintainability. And chapter 5 expanded ...