Commit Format

Commit Message Format

All commits MUST follow the Conventional Commits specification.

Format Structure

<type>(<scope>): <description>

[optional body]

[optional footer]

Format Rules

• Type (required): One of the types below, lowercase
• Scope (optional, but recommended): Area of codebase affected, lowercase, in parentheses
• Description (required): Short summary in imperative mood (e.g., "Add feature" not "Added feature")
• Body (optional): Detailed explanation, wrapped at 72 characters
• Footer (optional): Breaking changes or issue references

Commit Types

• feat: New feature for users
• fix: Bug fix
• docs: Documentation changes
• style: Code style changes (formatting, whitespace, etc.)
• refactor: Code refactoring (no feature change or bug fix)
• perf: Performance improvements
• test: Adding or updating tests
• build: Build system or dependency changes
• ci: CI/CD configuration changes
• chore: Other changes (maintenance tasks, tooling, etc.)

Common Scopes

Scopes help categorize commits by area of the codebase. Examples:

• api: API layer
• auth: Authentication/authorization
• db: Database related
• ui: User interface components
• core: Core business logic
• utils: Utility functions
• tests: Test files
• docs: Documentation
• scripts: Scripts and tooling
• config: Configuration files
• deps: Dependencies

Note: Choose scopes that match your project structure. Scopes should be lowercase and descriptive.

Examples

Feature Commits

feat(api): Add GET /health endpoint
feat(auth): Implement OAuth2 authentication
feat(ui): Add user dashboard component
feat(core): Add data validation layer

Fix Commits

fix(api): Handle shutdown state in health endpoint
fix(db): Correct connection pool timeout
fix(ui): Fix form validation error display
fix(core): Resolve race condition in cache

Documentation Commits

docs(readme): Update setup instructions
docs(api): Add API endpoint documentation
docs(contributing): Add contribution guidelines

Test Commits

test(api): Add integration tests for health endpoint
test(core): Add unit tests for validation layer
test(ui): Add component rendering tests

Refactoring Commits

refactor(core): Extract validation logic into separate module
refactor(api): Simplify error handling middleware
refactor(db): Optimize query performance

Multi-scope Commits

When changes span multiple areas, use the primary scope or omit scope:

feat: Implement authentication with API and UI updates
fix: Resolve validation errors across core and api modules

Detailed Commits (with body)

feat(api): Implement GET /health endpoint

- Track server start time for uptime calculation
- Track shutdown state for unhealthy status (503)
- Return status, timestamp (ISO 8601), uptime_seconds, version
- Complete within 100ms

Tests:
- Add 5 integration tests for health endpoint
- Test healthy status (200), timestamp format, uptime precision
- Test response time (<100ms), shutdown status (503)

Files:
- src/api/main.py: Add /health endpoint with state tracking
- tests/integration/api/test_health.py: Add comprehensive tests
- docs/api.md: Update API documentation

Best Practices

1. Be specific: "Add health endpoint" is better than "Update API"
2. Use imperative mood: "Add feature" not "Added feature" or "Adds feature"
3. Keep first line short: < 72 characters when possible
4. Include scope: Helps categorize and filter commits
5. Reference acceptance criteria: Use AC-X.Y.Z format when applicable
6. List files changed: Especially useful for larger commits
7. Group related changes: One logical change per commit

When to Use Each Type

• feat: New functionality that users/consumers will see or use
• fix: Correcting bugs or incorrect behavior
• docs: Only documentation (README, comments, plans, etc.)
• test: Only test files (new tests, test updates, test infrastructure)
• refactor: Code restructuring without changing behavior
• chore: Maintenance tasks, dependency updates, tooling changes

Multiple Commits for Large Changes

For large features, you may make multiple commits:

feat(api): Implement GET /health endpoint
test(api): Add integration tests for health endpoint
docs(api): Update API documentation

Or combine into a single detailed commit if all changes are tightly coupled.

Common Edge Cases

Handling Breaking Changes

Use the BREAKING CHANGE: footer for breaking changes:

feat(api): Change response format

BREAKING CHANGE: Response now uses snake_case instead of camelCase

Referencing Issues

Reference issues in the footer:

fix(game): Resolve validation bug

Fixes #123

Combining Multiple Related Changes

When multiple related files are changed for a single feature:

feat(core): Add timeout handling

- Add timeout configuration to service layer
- Implement timeout enforcement with ThreadPoolExecutor
- Add fallback mechanisms for each service stage

Files:
- src/core/service.py: Core timeout logic
- tests/integration/test_service.py: Timeout tests
- docs/architecture.md: Update architecture documentation