Git Commit Message Skill

Generate conventional, informative commit messages for Java projects.

When to Use

• After making code changes
• User says "commit this" / "commit changes" / "create commit"
• Before creating PRs

Format Standard

Use Conventional Commits format:

<type>(<scope>): <subject>

<body>

<footer>

Types (Java context)

• feat: New feature (new API, new functionality)
• fix: Bug fix
• refactor: Code refactoring (no functional change)
• test: Add/update tests
• docs: Documentation only
• perf: Performance improvement
• build: Maven/Gradle changes
• chore: Maintenance (dependency updates, etc)

Scope Examples (Java specific)

• Module name: core, api, plugin-loader
• Component: PluginManager, ExtensionFactory
• Area: lifecycle, dependencies, security

Subject Rules

• Imperative mood: "Add support" not "Added support"
• No period at end
• Max 50 chars
• Lowercase after type

Body (optional but recommended)

• Explain WHAT and WHY, not HOW
• Wrap at 72 chars
• Reference issues: "Fixes #123" / "Relates to #456"

Examples

Simple fix

fix(plugin-loader): prevent NPE when plugin directory is missing

Check for null before accessing plugin directory to avoid
NullPointerException during initialization.

Fixes #234

Feature with breaking change

feat(api): add support for plugin dependencies versioning

BREAKING CHANGE: PluginDescriptor now requires semantic versioning
format (x.y.z) instead of free-form version strings.

Closes #567

Refactoring

refactor(core): extract plugin validation logic

Move validation logic from PluginManager to separate
PluginValidator class for better testability and separation
of concerns.

Test addition

test(plugin-loader): add integration tests for plugin loading

Add comprehensive integration tests covering:
- Loading from directory
- Loading from JAR
- Error handling for invalid plugins

Build/dependency update

build(deps): upgrade Spring Boot to 3.2.1

Update Spring Boot from 3.1.0 to 3.2.1 for security patches
and performance improvements.

Workflow

1. Analyze changes using git diff --staged
2. Identify scope from modified files
3. Determine type based on change nature
4. Generate message following format
5. Execute commit: git commit -m "message"

Token Optimization

• Read staged changes ONCE: git diff --staged --stat + targeted file diffs
• Don't read entire files unless necessary
• Use concise body - aim for 2-3 lines max
• Batch multiple small changes into logical commits

Anti-patterns

❌ Avoid:

• "fix stuff" / "update code" / "changes"
• "WIP" commits (unless explicitly requested)
• Mixing unrelated changes (use separate commits)
• Over-detailed technical implementation in message

✅ Good commits:

• Single logical change
• Clear, searchable subject
• References issues when applicable
• Explains business value

Integration with GitHub

After commit, suggest next steps:

• "Push changes?"
• "Create PR for issue #X?"
• "Continue with next task?"

Common Patterns for Java Projects

Adding new functionality

feat(extension): add support for prioritized extensions

Allow extensions to specify priority order for execution.
Extensions with higher priority run first.

Closes #123

Fixing bugs

fix(classloader): resolve resource lookup in nested JARs

ClassLoader.getResource() was failing for resources in
JARs loaded from plugin JARs (nested JARs). Fixed by
implementing proper resource resolution chain.

Fixes #456

Dependency updates

build(deps): bump slf4j from 1.7.30 to 2.0.9

Updates SLF4J to latest stable version. No API changes
required as we use only stable APIs.

Documentation improvements

docs(readme): add plugin development quickstart guide

Add step-by-step guide for creating first plugin:
- Project setup
- Implementing Plugin interface
- Building and testing

Performance optimizations

perf(plugin-loader): cache plugin descriptors

Cache parsed plugin descriptors to avoid repeated I/O
and parsing. Reduces plugin loading time by ~40%.

Related to #789

Multi-file Changes

When changes span multiple components:

refactor(core): reorganize plugin lifecycle management

- Extract lifecycle state machine to separate class
- Move validation logic to validators package
- Update tests to reflect new structure

This refactoring improves testability and separation
of concerns without changing external APIs.

Related to #111, #222

Breaking Changes

Always use BREAKING CHANGE footer:

feat(api)!: replace Plugin.start() with Plugin.initialize()

BREAKING CHANGE: The Plugin.start() method has been renamed
to Plugin.initialize() for better semantic clarity. All
plugin implementations must update their code.

Migration guide: Replace @Override start() with @Override
initialize() in all Plugin implementations.

Closes #999

Quick Reference Card

References

• Conventional Commits Specification