Boy Scout Rule

The Principle

• Leave the codebase in better shape than you found it. If you see something wrong while doing something else, fix it
• "Pre-existing" is not a valid concept. The state you observed is the state you own, regardless of who or what put it there
• Applies to anything you'd flag if a colleague had just written it: failing tests, broken docs, dead code, stale comments, lying type signatures, leaked secrets, missing newlines, unbumped versions

Why "Pre-existing" Is Cope

• Most bypass attempts and gate-evasion patterns ("not my regression", "pre-existing", "out of scope for this PR") share this framing. Patching the bypass paths individually plays whack-a-mole; ruling out the framing closes the source. The bypass paths themselves are forbidden separately by rules/ci-safety.md's "Never Skip Tests" and rules/context-artifacts.md's "Disagreeing With the Reviewer"
• "I didn't break it" is true and irrelevant — the question is whether you'll leave it broken when you walk away. The repo doesn't care who broke it; it cares whether it's broken when the next person reads it
• Quality gates measure the merged state, not the delta. Treating gates as "your delta only" rots them on the same timescale as bypassing them outright

How to Apply

• In-scope cleanups (typo, missing newline, broken doc link, small drift): roll into the current PR. The bundle is fine when the PR's stated scope still reads coherently
• Out-of-scope discoveries (untested module, contradicting rules, unrelated security gap): open a follow-up PR — or an issue if the fix needs design — and reference it from the current one. Walking away with no record is the failure mode this rule prevents
• When unsure whether to bundle or split, prefer bundle small + cite or split large + file. The wrong answer is "leave it"

Reconciliation With commit-conventions

• rules/commit-conventions.md's "Keep PRs focused" and this rule appear to conflict. They don't. Focus governs the SHAPE of the bundle (one logical change per commit / PR); boy-scout governs whether you walk away from problems you noticed (no, you don't)
• A focused PR can include adjacent cleanup commits when the scope reads as one cohesive change. A focused PR cannot include unrelated rewrites — but it CAN include a follow-up reference to where those are tracked