Maintainability is a foundational quality of an automated test: it measures how easily the test can be understood and kept operational. Smaller tests are generally easier to read, while fewer out-of-process dependencies make them easier to run and maintain. section 4.6
Evaluate maintainability through two practical questions:
- Can a reader understand the test without reconstructing unnecessary setup or implementation detail? section 4.6
- Can the test run reliably without reaching across many out-of-process dependencies? section 4.6
- Prefer tests that retain maintainability and resistance to refactoring, then balance regression protection against fast feedback. section 4.4
Readable versus brittle tests
A trivial property test is short and fast but offers little regression protection. A repository test that asserts the exact SQL statement can detect regressions, yet couples the test to implementation details and becomes brittle during refactoring. Prefer asserting the resulting behavior rather than the internal SQL construction, while keeping the test understandable and operational. section 4.6
Value estimate = [0..1] * [0..1] * [0..1] * [0..1]
Use the value estimate to remember that a test scoring zero on maintainability or another foundational attribute has no overall value. section 4.4
