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

Analyze changes using git diff --staged
Identify scope from modified files
Determine type based on change nature
Generate message following format
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

Change Type	Type	Example Scope
New feature	feat	api, core, loader
Bug fix	fix	plugin-loader, lifecycle
Refactoring	refactor	core, utils
Tests	test	integration, unit
Docs	docs	readme, javadoc
Build	build	maven, deps
Performance	perf	classloader, cache
Maintenance	chore	ci, tooling

References

Conventional Commits Specification

git-commit