git-commit-guardian

# Git Commit Guardian Enforces professional commit message standards with Conventional Commits format and prevents AI attribution pollution. ## Core Mission This skill ensures every commit follows industry best practices while **eliminating Claude Code's default commit pollution** (co-author lines, generated-by footers). Commits should be clean, professional, and follow the Conventional Commits specification. **Problem Solved:** Claude Code by default adds "Generated with Claude Code" footers and "Co-Authored-By: Claude" lines to every commit. This pollutes git history and exposes AI usage unnecessarily. This skill blocks such patterns and enforces clean commits. ## Instructions ### 1. Intercept Commit Intent **Detect when user wants to commit:** - Direct: "commit", "git commit", "commit changes" - Indirect: "push this", "save changes to git", "create a commit" - After completing work: "done, commit it" **Immediately activate and validate before any commit action.** ### 2. Analyze Staged Changes **Before crafting commit message:** ```bash # View staged files git diff --cached --name-only # View actual changes git diff --cached # Check for sensitive files (BLOCK if found) git diff --cached --name-only | grep -E '\.(env|pem|key|credentials)$' ``` **Determine appropriate commit type from changes:** - New files with features → `feat` - Bug fixes → `fix` - Only docs/comments → `docs` - Only formatting → `style` - Code restructure, no behavior change → `refactor` - Performance improvements → `perf` - Test additions/fixes → `test` - Build system changes → `build` - CI configuration → `ci` - Maintenance/chores → `chore` ### 3. Validate Commit Message Format **Required format (Conventional Commits):** ``` <type>[(scope)][!]: <description> [optional body] [optional footer] ``` **Validation checklist:** - [ ] Type is valid: `feat|fix|docs|style|refactor|perf|test|build|ci|chore|revert` - [ ] Subject line ≤72 characters - [ ] Subject does NOT end with period - [ ] Subject uses imperative mood ("add" not "added", "fix" not "fixed") - [ ] Blank line between subject and body (if body exists) - [ ] Body lines wrapped at 80 characters - [ ] Breaking changes marked with `!` or `BREAKING CHANGE:` footer **If validation fails:** ``` COMMIT BLOCKED - Format Error Subject line exceeds 72 characters (currently: 85) Fix: Shorten to: "feat(compiler): add generic type support" Original: "feat(compiler): add generic type parameter support for class-level generics in IR generation" ``` ### 4. BLOCK Forbidden Patterns (CRITICAL) **These patterns MUST NEVER appear in commits:** ``` FORBIDDEN PATTERNS - ALWAYS BLOCK 1. AI Attribution Footer: "Generated with [Claude Code]" "Generated with Claude Code" "Generated by Claude" "Generated by AI" 2. Co-Author Lines (any variation): "Co-Authored-By: Claude" "Co-authored-by: Claude" "Co-Authored-By: Claude Opus" "Co-Authored-By: Claude Sonnet" "Co-authored-by:.*Claude" "Co-authored-by:.*Anthropic" "Co-Authored-By:.*noreply@anthropic.com" 3. Emoji AI Markers: Lines starting with robot emoji followed by "Generated" ``` **If forbidden pattern detected:** ``` COMMIT BLOCKED - AI Attribution Detected Found forbidden pattern in commit message: Line 5: "Co-Authored-By: Claude <noreply@anthropic.com>" This project requires clean commits without AI attribution. Remove the offending lines and retry. Allowed footers: Closes #123, Fixes #456, BREAKING CHANGE: ``` **This is NON-NEGOTIABLE. Always strip these before committing.** ### 5. Craft Clean Commit Message **Message structure:** ``` <type>(<scope>): <imperative description> <optional body explaining what and why> <optional footer: Closes #123, BREAKING CHANGE:, etc.> ``` **Good examples:** ``` feat(compiler): add generic type parameter support Implements class-level generic handling in IR generation. Method-level generics use identity function pattern. Closes #42 ``` ``` fix(fir): resolve annotation detection for nested interfaces The FIR phase was not traversing nested interface declarations. Added recursive visitor pattern to detect @Fake at all levels. ``` ``` refactor(generation): extract factory generation to dedicated class Separates concerns between implementation and factory generation for better maintainability and testing. ``` ``` docs: update installation guide for Gradle 8.x ``` **Bad examples (NEVER produce these):** ``` Add generic type parameter support Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com> ``` ``` Updated some stuff ``` ``` fix bug. ``` ### 6. Execute Commit **Only after all validations pass:** ```bash git commit -m "$(cat <<'EOF' <validated commit message here> EOF )" ``` **Verify commit succeeded:** ```bash git log -1 --format="%H %s" ``` **Output confirmation:** ``` COMMIT SUCCESSFUL Commit: a1b2c3d Message: feat(compiler): add generic type parameter support All validations passed: - Conventional Commits format - Subject: 47/72 characters - No forbidden patterns - Clean commit history maintained ``` ### 7. Handle Edge Cases **Multiple logical changes:** ``` Recommend splitting into multiple commits: 1. refactor(types): extract TypeResolver to separate file 2. feat(types): add variance handling for generic bounds 3. test(types): add unit tests for TypeResolver Use: git add -p (patch mode) to stage selectively ``` **Breaking changes:** ``` feat(api)!: change factory function signature BREAKING CHANGE: fakeXxx() now requires explicit configuration. Migration: fakeXxx() → fakeXxx {} ``` **Reverting commits:** ``` revert: feat(compiler): add generic type parameter support This reverts commit a1b2c3d. Reason: Causing compilation errors in multi-module projects. ``` ## Supporting Files Progressive disclosure for detailed documentation: - **`resources/conventional-commits-reference.md`** - Full Conventional Commits specification - **`resources/commit-message-patterns.md`** - Project-specific good/bad examples ## Related Skills This skill composes with: - **`bdd-test-runner`** - Run tests before committing - **`compilation-validator`** - Validate code compiles before committing This skill enables: - Clean git history - Professional commit messages - Automated changelog generation (from conventional commits) - Semantic versioning automation ## Best Practices 1. **One logical change per commit** - Don't bundle unrelated changes 2. **Write for future readers** - Explain why, not just what 3. **Use imperative mood** - "add feature" not "added feature" 4. **Keep subject concise** - 72 chars max, aim for 50 5. **Never include AI attribution** - Clean, professional commits only 6. **Reference issues when relevant** - `Closes #123`, `Fixes #456` 7. **Mark breaking changes explicitly** - Use `!` or `BREAKING CHANGE:` footer ## Commit Type Reference | Type | When to Use | Example | |------|-------------|---------| | `feat` | New feature for users | `feat(dsl): add configure block for behaviors` | | `fix` | Bug fix for users | `fix(ir): resolve null pointer in type resolution` | | `docs` | Documentation only | `docs: add KMP setup guide` | | `style` | Formatting, no logic change | `style: apply ktfmt formatting` | | `refactor` | Code restructure, same behavior | `refactor: extract visitor to separate class` | | `perf` | Performance improvement | `perf(analysis): cache interface metadata` | | `test` | Adding/fixing tests | `test: add generic bounds test cases` | | `build` | Build system, dependencies | `build: upgrade Kotlin to 2.1.0` | | `ci` | CI configuration | `ci: add KMP matrix to GitHub Actions` | | `chore` | Maintenance, tooling | `chore: update .gitignore patterns` | | `revert` | Reverting previous commit | `revert: feat(api): change return type` | ## Error Messages ### Invalid Type ``` COMMIT BLOCKED - Invalid Commit Type "update" is not a valid Conventional Commits type. Valid types: feat, fix, docs, style, refactor, perf, test, build, ci, chore, revert Suggested fix: "feat: ..." or "fix: ..." depending on change nature ``` ### Subject Too Long ``` COMMIT BLOCKED - Subject Exceeds 72 Characters Current: 89 characters Limit: 72 characters Original: "feat(compiler): implement comprehensive generic type parameter support for all interface variations" Suggested: "feat(compiler): add generic type parameter support" ``` ### AI Attribution Detected ``` COMMIT BLOCKED - AI Attribution Detected Line 4: "Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>" This project maintains clean commits without AI attribution. Remove this line to proceed. ``` ## Known Limitations - Skill activates on keyword detection; may miss indirect commit references - Cannot enforce rules if user bypasses skill and runs raw git commands - Body line wrapping is advisory (80 chars) not strictly enforced ## References - **Conventional Commits Spec**: https://www.conventionalcommits.org/ - **Git Best Practices**: https://cbea.ms/git-commit/ - **Angular Commit Guidelines**: https://github.com/angular/angular/blob/main/CONTRIBUTING.md#commit