Coverage Ratchet - CI/CD Glossary Definition
A coverage ratchet lets test coverage only go up: a change that drops it below the recorded baseline fails CI, while the baseline advances whenever coverage improves.
A coverage ratchet is a CI policy that fails a change if it lowers test coverage below the current baseline, allowing coverage to rise over time but never regress.
Ratcheting avoids arguing over an absolute target by locking in gains incrementally.
Why relative beats absolute
A fixed 80 percent threshold either blocks legacy work or is trivially met; a ratchet ties the gate to the current baseline, so each change must not make things worse and the number climbs organically.
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