Git Commit Assistant Skill

Purpose

Provide comprehensive Git commit assistance with:

• Automatic .gitignore validation and updates
• Intelligent file classification
• High-quality Conventional Commits message generation
• Protection against committing sensitive files

Activation Triggers

Automatically activate when:

• User says "commit", "git commit", "コミット", "コミットしたい"
• User mentions ".gitignore"
• User asks about what to commit/exclude
• User requests to push changes to remote

Workflow

Phase 1: Repository Analysis

1. Check Git status

   • Run git status --porcelain to get machine-readable output
   • Identify modified, deleted, untracked files
   • Check current branch with git branch --show-current
   • Verify repository is not in detached HEAD state

2. Analyze .gitignore

   • Read existing .gitignore (if present)
   • Check against known critical patterns from rules/gitignore-patterns.md
   • Identify missing critical patterns (credentials, MCP configs, personal settings)

3. Classify files

   • AUTO_EXCLUDE: Sensitive/environment-specific files (never commit)
   • AUTO_COMMIT: Obviously safe files (source code, docs, configs)
   • CONFIRM: Ambiguous files requiring user input

Phase 2: .gitignore Management

1. Check for sensitive patterns

   Critical patterns that must be present:

   • Credentials: *.key, *.pem, *credentials*, *secret*, .env
   • MCP configs: .claude.json, .mcp.json*
   • Personal settings: settings.json, settings.local.json
   • Build artifacts: node_modules/, dist/, *.log
   • OS files: .DS_Store, Thumbs.db

2. Propose .gitignore updates

   • Show missing patterns
   • Explain why each pattern is needed (security, environment dependency)
   • Ask user to approve updates using AskUserQuestion

3. Update .gitignore

   • Apply approved patterns
   • Stage .gitignore if updated

Phase 3: File Selection

1. Auto-classify files using rules

   AUTO_EXCLUDE (never commit):

   • Pattern: *credentials*, *.key, *.pem, *secret*, *password*
   • Pattern: .claude.json, .mcp.json*
   • Pattern: settings.json, settings.local.json
   • Pattern: .env, .env.local, .env.*.local
   • Pattern: node_modules/, vendor/, dist/, build/
   • Pattern: *.log, *.cache
   • Pattern: .DS_Store, Thumbs.db, desktop.ini

   AUTO_COMMIT (generally safe):

   • Pattern: *.md (documentation)
   • Pattern: .gitignore, .editorconfig
   • Pattern: src/**, internal/**, lib/** (source code)
   • Pattern: *_test.go, *.test.ts, *.test.tsx (tests)
   • Pattern: package.json, go.mod, Cargo.toml (manifests)
   • Pattern: .github/workflows/* (CI configs)
   • Pattern: ~/.claude/skills/** (Skills)
   • Pattern: ~/.claude/knowledge/** (Knowledge base)

   CONFIRM (user decision):

   • Files > 1MB
   • New directories
   • Executable files
   • Config files (not in AUTO lists)

2. User confirmation for ambiguous files

   • Present clear options using AskUserQuestion
   • Show file contents preview if helpful
   • Allow multi-select when appropriate

3. Final file list

   • Compile files to commit
   • Show summary to user before proceeding

Phase 4: Commit Message Generation

1. Analyze changes

   • Review git diff --cached for staged changes
   • Review git status for file operations (add, delete, rename)
   • Identify change patterns and scope

2. Determine commit type

   Follow Conventional Commits specification:

   • feat: New features or capabilities
   • fix: Bug fixes
   • docs: Documentation only changes
   • style: Formatting, whitespace, no code change
   • refactor: Code restructuring without behavior change
   • perf: Performance improvements
   • test: Adding or updating tests
   • build: Build system or external dependency changes
   • ci: CI configuration changes
   • chore: Maintenance tasks, dependency updates

3. Generate message

   Template structure:

   <type>(<scope>): <subject>
   
   - <bullet point 1>
   - <bullet point 2>
   - <bullet point 3>
   
   🤖 Generated with [Claude Code](https://claude.com/claude-code)
   
   Co-Authored-By: Claude <noreply@anthropic.com>
   

   Guidelines:

   • Subject: Concise, imperative mood, max 50 chars (English preferred)
   • Bullets: Japanese OK, explain what/why/impact
   • 3-5 bullets typically sufficient
   • No file lists (git handles that)
   • No emojis except attribution

4. Review with user

   • Show generated message
   • Allow edits if needed

Phase 5: Commit & Push

1. Stage files

   • Use git add for new/modified files
   • Use git rm for deleted files
   • Handle renames properly (git detects automatically)

2. Create commit

   • Apply generated message using heredoc for proper formatting
   • Example: git commit -m "$(cat <<'EOF'\n...\nEOF\n)"
   • Verify commit success

3. Optionally push

   • Check if remote exists: git remote -v
   • Check if branch tracks remote: git branch -vv
   • Ask user if should push
   • Execute git push origin <branch> if approved

File Classification Details

AUTO_EXCLUDE Priority Checks

1. Credentials/Secrets (Highest priority)

   • Any file containing "credential", "secret", "password", "key"
   • .env files
   • *.pem, *.key files
   • Action: Exclude immediately, warn user, ensure in .gitignore

2. MCP Configuration (High priority)

   • .claude.json, .mcp.json, .mcp.json.backup
   • Reason: Contains local environment paths
   • Action: Exclude, ensure in .gitignore

3. Personal Settings (High priority)

   • settings.json, settings.local.json
   • IDE settings: .vscode/settings.json, .idea/workspace.xml
   • Action: Exclude, ensure in .gitignore

4. Build Artifacts (Medium priority)

   • node_modules/, vendor/, dist/, build/
   • *.log, *.cache, coverage/
   • Action: Exclude, ensure in .gitignore

AUTO_COMMIT Safe Patterns

1. Documentation

   • *.md, docs/**
   • Reason: Shareable knowledge
   • Action: Commit

2. Source Code

   • src/**, internal/**, lib/**
   • *_test.go, *.test.ts, *.test.tsx
   • Reason: Core project files
   • Action: Commit

3. Configuration (Shareable)

   • .gitignore, .editorconfig, .prettierrc
   • package.json, tsconfig.json, go.mod
   • .github/workflows/**
   • Reason: Team-shared configuration
   • Action: Commit

4. Skills & Knowledge

   • ~/.claude/skills/**
   • ~/.claude/knowledge/**
   • Reason: Shareable expertise
   • Action: Commit

CONFIRM Cases

1. Large files (>1MB)

   • Show file size
   • Ask user if intentional
   • Suggest Git LFS if appropriate

2. New directories

   • Show directory contents (first level)
   • Ask user about purpose
   • Help classify based on purpose

3. Executable files

   • *.exe, *.bin, *.app
   • Ask if it's a build artifact or checked-in tool

Commit Message Quality Checks

Before finalizing:

1. Format validation

   • Verify Conventional Commits format: type(scope): subject
   • Check subject length (≤50 chars recommended)
   • Ensure imperative mood

2. Content validation

   • Verify bullets explain what/why/impact
   • Check for meaningful description (not just "update files")
   • Ensure proper attribution

3. Sensitive content scan

   • Scan diff for patterns like:
     • API keys: [A-Za-z0-9_-]{20,}
     • Passwords: password.*=.*
     • URLs with credentials: ://.*:.*@
   • Warn user if suspicious patterns found

Error Handling

Merge conflicts

• Detect: git status | grep "both modified"
• Action: Guide user to resolve first, offer to show conflict files

Detached HEAD

• Detect: git branch --show-current returns empty
• Action: Suggest creating branch with git switch -c <branch-name>

Nothing to commit

• Detect: git status --porcelain returns empty after staging
• Action: Inform clearly, suggest git status to check working directory

Uncommitted changes during checkout

• Detect: Error when switching branches
• Action: Offer to stash changes or commit them first

Integration with Global CLAUDE.md

Global CLAUDE.md should only contain:

## Git操作

コミットは `git-commit-assistant` Skill が支援する。
基本原則: Conventional Commits形式、絵文字不使用、必要十分な解説。
詳細は `~/.claude/skills/git-commit-assistant/SKILL.md` を参照。

All detailed rules, patterns, and templates are in this Skill's files.

Supporting Files

• rules/gitignore-patterns.md: Comprehensive .gitignore pattern library
• rules/file-classification.md: Detailed file classification rules
• templates/commit-message.md: Commit message template and examples

Usage Tips

When NOT to use this Skill

• Simple typo fixes in docs (just commit directly)
• When you want to commit with custom message format
• Emergency hotfixes (speed matters more than format)

When to DEFINITELY use this Skill

• First commit in new repo
• Committing to ~/.claude/ (high risk of exposing sensitive configs)
• Large changesets with multiple types of changes
• When unsure about what to commit/exclude

Maintenance

This Skill should be updated when:

• New file types need classification rules
• New sensitive patterns are discovered
• Commit message conventions evolve
• New tech stacks require specific patterns