PR Generator

Overview

Generate conventional commit-formatted PR titles and concise descriptions by analyzing git changes between branches. Uses gh CLI and git commands to gather information intelligently.

When to Use

• •Creating a new pull request
• •Summarizing changes between branches
• •Generating PR documentation for GitHub repositories
• •Preparing change summaries for code review

Workflow

Step 1: Gather Branch Information

Use gh and git commands to collect necessary data:

# Get current branch (if source not specified)
git branch --show-current

# Get merge base
git merge-base main <source_branch>

# Get commit messages
git log <merge_base>..<source_branch> --pretty=format:%s

# Get changed files
git diff --name-only --diff-filter=d <merge_base> <source_branch>

# Get file statistics
git diff --stat <merge_base> <source_branch>

For existing PRs, gather additional context:

gh pr view <pr_number> --json title,body,files

Step 2: Analyze Commits

Extract information from commit messages:

1. •Check for conventional commits - Look for <type>: or <type>(scope): pattern
2. •Identify main themes - Group related commits by functionality
3. •Count commits - Understand scope of changes

If commits follow conventional format, extract type and scope directly:

feat(auth): add login → type=feat, scope=auth, description=add login
fix: handle null → type=fix, scope=None, description=handle null

Step 3: Generate PR Title

Use conventional commit format: <type>[optional scope]: <description>

Type inference priority:

1. •Extract from existing conventional commit messages (most common type)
2. •Infer from file patterns:
   • •Test files (test/, *_test.py, *.spec.ts) → test
   • •Documentation (*.md, docs/) → docs
   • •Config (*.yaml, *.json, *.toml) → chore
   • •"fix"/"bug" in commit messages → fix
3. •Default to feat for new features

Title guidelines:

• •Use imperative mood: "add" not "added"
• •Capitalize first letter
• •Keep under 72 characters
• •Don't end with period

Examples:

feat: add user authentication
fix(api): handle rate limiting errors
docs: update installation guide
refactor(components): extract shared button logic
test: add unit tests for auth module

See references/conventional_commits.md for complete type reference.

Step 4: Generate PR Description

Create a concise, structured description:

Summary section:

• •High-level overview (2-3 sentences)
• •List main changes using commit messages (max 5 if many commits)
• •Focus on what and why, not how

Changed Files section:

• •Categorize files: Code, Tests, Config, Documentation, Scripts
• •Use file count: "Code (5 files):"
• •List file paths (truncate at 10 if extensive)
• •Mark type: src/api/auth.py vs docs/

Example:

## Summary

This PR implements user authentication with JWT tokens. Includes login/logout endpoints and session management.

Main changes:
- Add JWT-based authentication service
- Implement login/logout API endpoints
- Add session management middleware
- Create user model and database schema

## Changed Files

**Code** (5 files):
  - `src/api/auth.py`
  - `src/services/auth_service.py`
  - `src/middleware/session.py`
  - `src/models/user.py`
  - `src/utils/jwt.py`

**Tests** (2 files):
  - `tests/test_auth.py`
  - `tests/fixtures/auth.py`

**Config** (1 files):
  - `config/auth.yaml`

**Documentation** (1 files):
  - `docs/api/auth.md`

Step 5: Optional Enhancements

Include when relevant:

Breaking changes:

## Breaking Changes

- Remove deprecated `authenticate()` method
- Change `login()` signature to require email instead of username

Testing notes:

## Testing

- Login/logout with valid credentials
- Invalid credential handling
- Session persistence
- Token expiration behavior

Related issues:

Closes #123
Fixes #456

Important Notes

Context Preservation

Skip document file contents - Only list filenames:

• •.md, .txt, .rst, .adoc files
• •Don't read file content to preserve context

For extensive changes (50+ files, 1000+ lines):

• •Focus on recent commits
• •Truncate file lists at 10 per category
• •Summarize themes rather than listing all changes

Smart Analysis

When gathering information:

1. •Start with gh - If PR exists, use gh pr view for context
2. •Get commit count first - Decide how deep to analyze
3. •Sample commits - If >20 commits, check first 10 and last 5
4. •Categorize intelligently - Group related changes in summary

Example efficient workflow:

# Quick scope check
git log main..feature-branch --oneline | wc -l

# If >20 commits, sample instead of reading all
git log main..feature-branch --pretty=format:%s | head -10

# Get files (always safe)
git diff --name-only main feature-branch

# Only get detailed stats if needed
git diff --stat main feature-branch

Quality Checklist

Before finalizing:

• • Title uses conventional commit format
• • Title is concise (<72 chars)
• • Title capitalized correctly
• • Summary captures main changes
• • Files logically categorized
• • No redundancy between title and summary
• • Doc files listed, not read

Resources

references/conventional_commits.md

Quick reference for conventional commit types and formatting. Consult when:

• •Selecting appropriate commit type
• •Adding scope to title
• •Verifying title format
• •Explaining conventional commits to users

assets/pr_template.md

Basic PR template structure. Reference for common sections but not required for generated descriptions.