Code Quality Principles

Foundation skill governing code quality standards during autonomous development.

Iron Law

EVERY CHANGE MUST BE INTENTIONAL. If you can't explain why a line changed, revert it.

Always leave code better than you found it. Fix issues in files you are already modifying — but only changes that pass the proximity test.

Before You Write Code

Answer these questions first. If you can't, return to EXPLORE:

1. What is the specific task/criterion this code serves?
2. What files will be modified and why each one?
3. What existing patterns does this project use for this type of change?
4. What could go wrong? (error cases, edge cases, security)
5. How will you verify this works?

Boy Scout Rule

Leave every file you touch better than you found it. Fixing known defects in touched files is not optional scope creep — it is the baseline of Quality-First Completionism. Touching a file means owning its known issues.

The proximity test is NOT a deferral mechanism for P1/P2 findings. It decides how a cleanup is committed (alongside the feature fix vs. as a separate improve: commit), not whether it gets fixed. If a P1 or P2 finding exists in a file the PR modifies, it is fixed in this PR, full stop.

A cleanup is committed as a standalone `improve:` commit when ALL true:

1. The file is already being modified for the current task
2. The fix is self-evidently correct (lint, format, typo, obvious bug, missing error handling)
3. The fix is small (under ~10 lines of cleanup)
4. The fix does not change public API signatures or behavior semantics
5. The fix needs no explanation beyond "Boy Scout cleanup"

A finding requires expanded scope (still fixed, but may need a design note or additional tests) when ANY true:

1. Requires modifying files NOT already touched by the task
2. Changes architecture, module boundaries, or public APIs
3. Requires new tests to validate
4. Would benefit from its own issue to explain motivation
5. Is a subjective style preference (in which case it is P3 at most, not a fix-blocker)

For P1/P2 findings that fall into the "expanded scope" bucket: fix them in-PR with an appropriate commit message. Finding triage is NEVER a valid escalation trigger — do NOT file a six-field Proactive-Autonomy escalation to ask whether to fix a finding (see skills/llm-operator-principles/SKILL.md and references/escalation-format.md). "Disagree to fix" is not an option; "ask the user whether to fix" is also not an option.

Default mode: cosmetic P3 findings in truly untouched files are fixed if bounded (<10 lines) or documented inline in the PR body. Do NOT create follow-up issues for them.

Minimal-scope mode (`settings.json` → `minimalScope: true`): the original follow-up issue workflow for cosmetic P3 in untouched files is restored.

No Secrets in Code

Never commit secrets, credentials, or sensitive values:

• Use environment variables for API keys, tokens, passwords
• Use .env files (gitignored) for local development
• Reference secrets by name, never by value
• If you spot a hardcoded secret, flag it as P1 immediately

Production Code Standards

Code that ships must be complete:

• No TODO comments in committed code — track in issues instead
• No console.log / puts / print debugging statements
• No mocked or stubbed implementations ("implement later")
• No commented-out code blocks — delete or use version control
• No placeholder error messages ("Something went wrong")

Quality Command Execution

Run independent quality commands (lint, test, typecheck) as parallel Bash calls, never chained with &&. After quality checks: P1 failures fix immediately, P2 fix before PR, P3 fix in-PR by default. Finding triage is NEVER a valid escalation trigger (see references/escalation-format.md).

Anti-Patterns

Do NOT:

• Modify imports/formatting in files you aren't changing for the task
• Add improvements that fail the proximity test into the same PR
• Commit generated files without verifying they're correct
• Copy-paste code instead of extracting a shared function
• Catch exceptions silently (catch {} / rescue nil)

First-Touch Awareness

When a file has 0 prior commits on the branch and you're making large additions:

• Flag it as "first touch" in change classification
• Give it extra review attention — new files have no established patterns
• Ensure it follows the project's conventions (naming, structure, style)

Atomic Commits

Each commit should be a complete, valuable change:

• Can you describe it without saying "WIP" or "partial"?
• Does it leave the codebase in a working state?
• Would reverting it cleanly undo one logical change?

If yes to all three, commit. Otherwise, keep working.

Self-Review Checklist

Before marking any task complete:

1. git diff — only intended changes present?
2. No debug code or temporary files?
3. New code follows existing patterns in the project?
4. Edge cases considered (null, empty, boundary values)?
5. Error messages are helpful and specific?

Rationalization Prevention