unit-testinglisted

# Unit Testing (TDD · Microtests · ZOMBIES · Tidy First? · Eight Virtues) ## When to use this skill **Use `unit-testing` when:** - Implementing new behavior or extending existing behavior with production code - Bug fixes that require new logic (characterize with a failing test first) - Choosing the next test to write (ZOMBIES ordering) - Deciding whether to tidy before writing the next test (Tidy First?) - Refactoring production or test code toward the Eight Code Virtues within an active TDD cycle - Diagnosing flaky, slow, or poorly-structured tests using FIRST - Any session where you would otherwise "code then sprinkle tests" **Do NOT use `unit-testing` for:** - Establishing initial test access or characterizing poorly understood existing behavior → use `legacy-code-safety`, then return here - Choosing which delivery slice to build next → use `story-splitting-for-delivery` - Formatting an already-split story as user-visible outcomes → use `user-pov-sliced-stories` - Reviewing code broadly for representation or virtue violations without an active TDD cycle → use `representation-refactor-review` - Performing a focused identifier diagnosis or rename plan → use `code-object-naming` - Trunk-landing strategies, feature toggles, or branch-by-abstraction (out of scope for this package) --- ## Purpose and scope TDD is programming hygiene. Its job is not "prove the whole system" or "raise coverage." Its job is to keep code orderly and **safe to change in tiny steps** so you can