Correction and Cleanup (400 Series)

The 400 series handles two adjacent kinds of follow-up work:

• failure triage and correction when a red test does not clearly point to test or source
• cleanup-only refinement on an already-changed scope

The split

401 and 402 are different workflows:

• 401-cleanup: cleanup-only refinement on an existing changed set
• 402-test-correction: investigate a failing test and decide whether the right fix is in the test, in source, or in intended behavior

The 401 rule

One target type per run: source code or test code, never both.

This constraint keeps cleanup small, reviewable, and safe to roll back. When you want both source and test cleanup, run 401 twice — once for each.

Cleanup is not always necessary

301-spec-implementation already includes internal test and production cleanup phases before its final validation. Use 401 when you want an additional explicit cleanup pass, or when the internal cleanup was not sufficient for a particularly complex change.

402 is the red-test triage path

Use 402-test-correction when the problem starts with a failing automated test and you still need to determine whether the defect is in the test, in production code, or in the intended behavior. 402 should stop and ask when the failure is really a business-capability question instead of a clear defect.

Skills in this series

• 401 Cleanup — cleanup-only refinement on an already-changed scope
• 402 Test Correction — classify and correct a failing test without guessing the fix path