Changelog Generator

This skill generates and maintains changelogs following the Keep a Changelog format, integrated with Conventional Commits and Semantic Versioning.

Quick Start

When invoked, analyze git history and generate/update the changelog:

# Get commits since last tag
git log $(git describe --tags --abbrev=0 2>/dev/null || echo "")..HEAD --pretty=format:"%h %s" --no-merges

# Get all tags for reference
git tag --sort=-version:refname | head -10

Changelog Format (Keep a Changelog)

# Changelog

All notable changes to this project will be documented in this file.

The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## [Unreleased]

### Added
- New features

### Changed
- Changes in existing functionality

### Deprecated
- Soon-to-be removed features

### Removed
- Removed features

### Fixed
- Bug fixes

### Security
- Vulnerability fixes

## [1.1.0] - 2024-01-26

### Added
- New `zustand-state` skill for state management
- New `form-validation` skill with Zod + Conform integration
- New `security-hardening` skill for Shopify apps

### Changed
- Updated `shopify-developer` agent with new skills
- Updated `tech-lead` agent with security-hardening skill

## [1.0.4] - 2024-01-20

### Fixed
- Initial stable release

[Unreleased]: https://github.com/user/repo/compare/v1.1.0...HEAD
[1.1.0]: https://github.com/user/repo/compare/v1.0.4...v1.1.0
[1.0.4]: https://github.com/user/repo/releases/tag/v1.0.4

Conventional Commits Mapping

Map commit prefixes to changelog categories:

Commit Prefix        →  Changelog Category
─────────────────────────────────────────────
feat:                →  Added
fix:                 →  Fixed
docs:                →  Changed (Documentation)
style:               →  Changed (Formatting)
refactor:            →  Changed
perf:                →  Changed (Performance)
test:                →  (Usually omitted)
build:               →  Changed (Build system)
ci:                  →  (Usually omitted)
chore:               →  (Usually omitted)
revert:              →  Removed or Fixed
security: / vuln:    →  Security
deprecate:           →  Deprecated
remove: / breaking:  →  Removed

Generation Process

Step 1: Analyze Git History

# Get commits since last release
git log v1.0.4..HEAD --pretty=format:"%H|%s|%an|%ad" --date=short

# Or since a specific date
git log --since="2024-01-01" --pretty=format:"%H|%s|%an|%ad" --date=short

Step 2: Categorize Changes

Parse each commit message and categorize:

interface ChangeEntry {
  category: 'Added' | 'Changed' | 'Deprecated' | 'Removed' | 'Fixed' | 'Security';
  description: string;
  commit: string;
  scope?: string;
  breaking?: boolean;
}

function categorizeCommit(message: string): ChangeEntry | null {
  const conventionalRegex = /^(\w+)(?:\(([^)]+)\))?(!)?:\s*(.+)$/;
  const match = message.match(conventionalRegex);

  if (!match) return null;

  const [, type, scope, breaking, description] = match;

  const categoryMap: Record<string, ChangeEntry['category']> = {
    feat: 'Added',
    fix: 'Fixed',
    docs: 'Changed',
    style: 'Changed',
    refactor: 'Changed',
    perf: 'Changed',
    security: 'Security',
    deprecate: 'Deprecated',
    remove: 'Removed',
  };

  return {
    category: categoryMap[type] || 'Changed',
    description,
    scope,
    breaking: !!breaking,
  };
}

Step 3: Generate Markdown

function generateChangelog(entries: ChangeEntry[], version: string, date: string): string {
  const grouped = groupBy(entries, 'category');
  const order = ['Added', 'Changed', 'Deprecated', 'Removed', 'Fixed', 'Security'];

  let output = `## [${version}] - ${date}\n\n`;

  for (const category of order) {
    if (grouped[category]?.length) {
      output += `### ${category}\n`;
      for (const entry of grouped[category]) {
        const scope = entry.scope ? `**${entry.scope}:** ` : '';
        const breaking = entry.breaking ? '⚠️ BREAKING: ' : '';
        output += `- ${breaking}${scope}${entry.description}\n`;
      }
      output += '\n';
    }
  }

  return output;
}

Version Determination

Based on changes, suggest version bump:

Change Type                →  Version Bump    →  Example
────────────────────────────────────────────────────────────
Breaking changes (!)       →  MAJOR           →  1.0.0 → 2.0.0
New features (feat)        →  MINOR           →  1.0.0 → 1.1.0
Bug fixes (fix)            →  PATCH           →  1.0.0 → 1.0.1
Other changes              →  PATCH           →  1.0.0 → 1.0.1

function suggestVersionBump(entries: ChangeEntry[], currentVersion: string): string {
  const [major, minor, patch] = currentVersion.split('.').map(Number);

  if (entries.some(e => e.breaking)) {
    return `${major + 1}.0.0`;
  }
  if (entries.some(e => e.category === 'Added')) {
    return `${major}.${minor + 1}.0`;
  }
  return `${major}.${minor}.${patch + 1}`;
}

Workflow Integration

Pre-release Workflow

# 1. Generate changelog for unreleased changes
git log $(git describe --tags --abbrev=0)..HEAD --oneline

# 2. Update CHANGELOG.md with new version section

# 3. Commit changelog
git add CHANGELOG.md
git commit -m "docs: update changelog for v1.2.0"

# 4. Create version tag
git tag -a v1.2.0 -m "Release v1.2.0"

# 5. Push with tags
git push --follow-tags

GitHub Release Integration

Generate release notes for GitHub:

# Extract latest version section from CHANGELOG.md
sed -n '/^## \[1\.2\.0\]/,/^## \[/p' CHANGELOG.md | head -n -1

# Create GitHub release
gh release create v1.2.0 --title "v1.2.0" --notes-file release-notes.md

Output Formats

Markdown (Default)

Standard Keep a Changelog format as shown above.

JSON

{
  "version": "1.1.0",
  "date": "2024-01-26",
  "changes": {
    "added": [
      "New `zustand-state` skill for state management",
      "New `form-validation` skill with Zod + Conform integration"
    ],
    "changed": [
      "Updated `shopify-developer` agent with new skills"
    ],
    "fixed": [],
    "security": []
  }
}

Release Notes (Simplified)

# Release v1.1.0

## Highlights
- 🎉 3 new skills added for better Shopify development

## What's New
- **zustand-state**: State management with Zustand
- **form-validation**: Form validation with Zod + Conform
- **security-hardening**: Security best practices

## Improvements
- Updated agents with new skill integrations

---
Full changelog: https://github.com/user/repo/blob/main/CHANGELOG.md

Best Practices

DO

• ✅ Write changelogs for humans, not machines
• ✅ Use present tense ("Add feature" not "Added feature")
• ✅ Group changes by type (Added, Changed, Fixed, etc.)
• ✅ Include links to issues/PRs when relevant
• ✅ Highlight breaking changes prominently
• ✅ Keep entries concise but descriptive

DON'T

• ❌ Include every single commit (filter noise)
• ❌ Use technical jargon without explanation
• ❌ Forget to update [Unreleased] section
• ❌ Mix different versions in one section
• ❌ Skip security-related changes

Commands Reference

# View commits since last tag
git log $(git describe --tags --abbrev=0)..HEAD --oneline

# View commits between two tags
git log v1.0.0..v1.1.0 --oneline

# Get commit count by type
git log --oneline | grep -E "^[a-f0-9]+ (feat|fix|docs):" | wc -l

# List all contributors since last release
git log $(git describe --tags --abbrev=0)..HEAD --format="%an" | sort -u

# Generate commit list with dates
git log --since="2024-01-01" --pretty=format:"- %s (%ad)" --date=short

Example Invocations

/changelog                    # Generate for unreleased changes
/changelog 1.2.0              # Generate for specific version
/changelog --since=v1.0.0     # Changes since specific tag
/changelog --format=json      # Output as JSON