Commit Message

Generate commit messages from staged changes

Generates commit messages from staged changes (git diff --staged). This command only creates messages and copies them to your clipboard—it doesn't run any git commands.

Usage

/commit-message [options]

Options

• --format <format> : Choose message format (conventional, gitmoji, angular)
• --lang <language> : Set language explicitly (en)
• --breaking : Include breaking change detection

Basic Examples

# Generate message from staged changes (language auto-detected)
# The top suggestion is automatically copied to your clipboard
/commit-message

# Specify language explicitly
/commit-message --lang ja
/commit-message --lang en

# Include breaking change detection
/commit-message --breaking

Prerequisites

Important: This command only works with staged changes. Run git add first to stage your changes.

# If nothing is staged, you'll see:
$ /commit-message
No staged changes found. Please run git add first.

Automatic Clipboard Feature

The top suggestion gets copied to your clipboard as a complete command: git commit -m "message". Just paste and run it in your terminal.

Implementation Notes:

• Run pbcopy in a separate process from the message output
• Use printf instead of echo to avoid unwanted newlines

Automatic Project Convention Detection

Important: If project-specific conventions exist, they take priority.

1. CommitLint Configuration Check

Automatically detects settings from the following files:

• commitlint.config.js
• commitlint.config.mjs
• commitlint.config.cjs
• commitlint.config.ts
• .commitlintrc.js
• .commitlintrc.json
• .commitlintrc.yml
• .commitlintrc.yaml
• package.json with commitlint section

# Search for configuration files
find . -name "commitlint.config.*" -o -name ".commitlintrc.*" | head -1

2. Custom Type Detection

Example of project-specific types:

// commitlint.config.mjs
export default {
  extends: ["@commitlint/config-conventional"],
  rules: {
    "type-enum": [
      2,
      "always",
      [
        "feat",
        "fix",
        "docs",
        "style",
        "refactor",
        "test",
        "chore",
        "wip", // work in progress
        "hotfix", // urgent fix
        "release", // release
        "deps", // dependency update
        "config", // configuration change
      ],
    ],
  },
};

3. Detecting Language Settings

// When project uses Japanese messages
export default {
  rules: {
    "subject-case": [0], // Disabled for Japanese support
    "subject-max-length": [2, "always", 72], // Adjusted character limit for Japanese
  },
};

4. Existing Commit History Analysis

# Learn patterns from recent commits
git log --oneline -50 --pretty=format:"%s"

# Type usage statistics
git log --oneline -100 --pretty=format:"%s" | \
grep -oE '^[a-z]+(\([^)]+\))?' | \
sort | uniq -c | sort -nr

Automatic Language Detection

Automatically switches between Japanese/English based on:

1. CommitLint configuration language settings
2. git log analysis automatic detection
3. Project file language settings
4. Changed file comment and string analysis

Default is English. Generates in Japanese if detected as Japanese project.

Message Format

Conventional Commits (Default)

<type>: <description>

Important: Always generates single-line commit messages. Does not generate multi-line messages.

Note: Project-specific conventions take priority if they exist.

Standard Types

Required Types:

• feat: New feature (user-visible feature addition)
• fix: Bug fix

Optional Types:

• build: Build system or external dependency changes
• chore: Other changes (no release impact)
• ci: CI configuration files and scripts changes
• docs: Documentation only changes
• style: Changes that don't affect code meaning (whitespace, formatting, semicolons, etc.)
• refactor: Code changes without bug fixes or feature additions
• perf: Performance improvements
• test: Adding or fixing tests

Output Example (English Project)

$ /commit-message

📝 Commit Message Suggestions
━━━━━━━━━━━━━━━━━━━━━━━━━

✨ Main Candidate:
feat: implement JWT-based authentication system

📋 Alternatives:
1. feat: add user authentication with JWT tokens
2. fix: resolve token validation error in auth middleware
3. refactor: extract auth logic into separate module

✅ `git commit -m "feat: implement JWT-based authentication system"` copied to clipboard

Implementation Example (Fixed):

# Copy commit command to clipboard first (no newline)
printf 'git commit -m "%s"' "$COMMIT_MESSAGE" | pbcopy

# Then display message
cat << EOF
📝 Commit Message Suggestions
━━━━━━━━━━━━━━━━━━━━━━━━━

✨ Main Candidate:
$COMMIT_MESSAGE

📋 Alternatives:
1. ...
2. ...
3. ...

✅ \`git commit -m "$COMMIT_MESSAGE"\` copied to clipboard
EOF

Output Example (Japanese Project)

$ /commit-message

📝 Commit Message Suggestions
━━━━━━━━━━━━━━━━━━━━━━━━━

✨ Main Candidate:
feat: JWT authentication system implemented

📋 Alternatives:
1. feat: add user authentication with JWT tokens
2. fix: resolve token validation error in auth middleware
3. docs: separate auth logic into different module

✅ `git commit -m "feat: JWT authentication system implemented"` copied to clipboard

Operation Overview

1. Analysis: Analyze content of git diff --staged
2. Generation: Generate appropriate commit message
3. Copy: Automatically copy main candidate to clipboard

Note: This command does not execute git add or git commit. It only generates commit messages and copies to clipboard.

Smart Features

1. Automatic Change Classification (Staged Files Only)

• New file addition → feat
• Error fix patterns → fix
• Test files only → test
• Configuration file changes → chore
• README/docs updates → docs

2. Automatic Project Convention Detection

• .gitmessage file
• Conventions in CONTRIBUTING.md
• Past commit history patterns

3. Language Detection Details (Staged Changes Only)

# Detection criteria (priority order)
1. Detect language from git diff --staged content
2. Comment analysis of staged files
3. Language analysis of git log --oneline -20
4. Project main language settings

4. Staging Analysis Details

Information used for analysis (read-only):

• git diff --staged --name-only - Changed file list
• git diff --staged - Actual change content
• git status --porcelain - File status

Breaking Change Detection

For breaking API changes:

English:

feat!: change user API response format

BREAKING CHANGE: user response now includes additional metadata

Or:

feat(api)!: change authentication flow

Japanese:

feat!: change user API response format

BREAKING CHANGE: response now includes additional metadata

Or:

feat(api)!: change authentication flow

Best Practices

1. Match project: Follow existing commit language
2. Conciseness: Clear within 50 characters
3. Consistency: Don't mix languages (stay consistent in English)
4. OSS: English recommended for open source
5. Single line: Always single-line commit message (supplement with PR for detailed explanations)

Common Patterns

English:

feat: add user registration endpoint
fix: resolve memory leak in cache manager
docs: update API documentation

Japanese:

feat: add user registration endpoint
fix: resolve memory leak in cache manager
docs: update API documentation

Integration with Claude

# Use with staged changes
git add -p  # Interactive staging
/commit-message
"Generate optimal commit message"

# Stage and analyze specific files
git add src/auth/*.js
/commit-message --lang en
"Generate message for authentication changes"

# Breaking Change detection and handling
git add -A
/commit-message --breaking
"Mark appropriately if there are breaking changes"

Important Notes

• Prerequisite: Changes must be staged with git add beforehand
• Limitation: Unstaged changes are not analyzed
• Recommendation: Check existing project commit conventions first