commit-message-generator

Commit Message Generator

Generate clear, conventional commit messages from git diffs.

Quick Start

Analyze staged changes and generate message:

git diff --staged
# Then generate message following conventional commits format

Instructions

Step 1: Analyze Changes

Review the git diff to understand:

• What files changed
• What functionality was added/modified/removed
• Scope of changes (component, module, feature)
• Breaking changes or deprecations

git diff --staged
# or for specific files
git diff --staged path/to/file

Step 2: Determine Commit Type

feat: New feature

• Adding new functionality
• New user-facing capability
• New API endpoint

fix: Bug fix

• Fixing a bug
• Correcting behavior
• Resolving an issue

docs: Documentation

• README updates
• Code comments
• API documentation

style: Code style

• Formatting changes
• Missing semicolons
• Whitespace changes
• No code logic changes

refactor: Code refactoring

• Restructuring code
• No functionality change
• Performance improvements

test: Tests

• Adding tests
• Updating tests
• Test infrastructure

chore: Maintenance

• Dependency updates
• Build configuration
• CI/CD changes
• Tooling updates

perf: Performance

• Performance improvements
• Optimization changes

ci: CI/CD

• CI configuration
• Build scripts
• Deployment changes

build: Build system

• Build tool changes
• External dependencies

revert: Revert

• Reverting previous commit

Step 3: Identify Scope

Scope indicates what part of codebase changed:

• Component name: (button), (navbar)
• Module name: (auth), (api)
• Feature area: (payments), (search)
• Package name: (core), (utils)

Optional but recommended for clarity.

Step 4: Write Description

Subject line (first line):

• Use imperative mood ("add" not "added")
• No period at end
• Max 50-72 characters
• Lowercase after type
• Clear and concise

Body (optional, after blank line):

• Explain what and why, not how
• Wrap at 72 characters
• Use bullet points for multiple changes
• Reference issues/tickets

Footer (optional):

• Breaking changes: BREAKING CHANGE: description
• Issue references: Closes #123, Fixes #456
• Co-authors: Co-authored-by: Name <email>

Step 5: Format Message

Basic format:

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

[optional body]

[optional footer]

Examples:

feat(auth): add JWT token refresh mechanism

Implement automatic token refresh when access token expires.
Tokens are refreshed 5 minutes before expiration.

Closes #234

fix(api): handle null response in user endpoint

Previously crashed when user data was null.
Now returns 404 with appropriate error message.

Fixes #567

docs(readme): update installation instructions

Add prerequisites section and troubleshooting guide.

refactor(utils): simplify date formatting logic

Extract common date operations into helper functions.
No functionality changes.

chore(deps): upgrade react to v18.2.0

Update react and react-dom dependencies.
Update tests to match new API.

Common Patterns

Multiple changes in one commit:

feat(dashboard): add user analytics and export

- Add analytics charts for user activity
- Implement CSV export functionality
- Add date range filter

Closes #123, #124

Breaking change:

feat(api)!: change authentication endpoint structure

BREAKING CHANGE: Auth endpoints now use /v2/auth prefix.
Update client code to use new endpoints.

Migration guide: docs/migration-v2.md

Revert commit:

revert: feat(auth): add JWT token refresh

This reverts commit abc123def456.
Reason: Causing issues in production.

Co-authored commit:

feat(search): implement fuzzy search algorithm

Co-authored-by: Jane Doe <[email protected]>

Commit Message Quality

Good commit messages:

• Clear and descriptive
• Explain why, not just what
• Reference related issues
• Follow conventions consistently
• Atomic (one logical change)

Bad commit messages:

• "fix stuff"
• "WIP"
• "updates"
• "asdf"
• "fix fix fix"

Workflow Integration

Before committing:

1. Review changes: git diff --staged
2. Ensure changes are atomic
3. Generate appropriate message
4. Commit: git commit -m "type(scope): description"

For detailed commits:

1. Stage changes: git add files
2. Open editor: git commit
3. Write multi-line message
4. Save and close

Amending last commit:

git commit --amend
# Edit message in editor

Interactive staging:

git add -p  # Stage hunks interactively
git commit  # Write message for staged changes

Conventional Commits Spec

Format: <type>[optional scope]: <description>

Required:

• type: Must be one of the defined types
• description: Brief summary of change

Optional:

• scope: Component/module affected
• body: Detailed explanation
• footer: Breaking changes, issue references

Rules:

• Type must be lowercase
• Scope in parentheses
• Colon and space after scope
• Description starts lowercase
• No period at end of description
• Body separated by blank line
• Footer separated by blank line

Advanced

For complex scenarios:

• Multi-commit features
• Monorepo commit conventions
• Automated commit message validation
• Commit message templates
• Semantic versioning integration