Smart PR Description Generator

Generate comprehensive, well-structured pull request descriptions by analyzing your git history and changes.

When to Activate

• User asks to create a PR description
• User says /smart-pr or "write a PR description"
• User is about to create a pull request and needs a description

Instructions

Step 1: Gather Context

Determine the base branch (default: main) and collect:

# Get the base branch
BASE_BRANCH="${1:-main}"

# Commits since diverging from base
git log --oneline "$BASE_BRANCH"..HEAD

# Full diff stats
git diff --stat "$BASE_BRANCH"..HEAD

# Detailed diff for analysis
git diff "$BASE_BRANCH"..HEAD

If there are no commits ahead of the base branch, inform the user and stop.

Step 2: Analyze Changes

Categorize each commit by type using conventional commit patterns:

Prefix	Category
feat: or new functionality	Features
fix: or bug repairs	Bug Fixes
refactor: or restructuring	Refactoring
test: or test changes	Testing
docs: or documentation	Documentation
chore:, ci:, deps	Maintenance
perf: or optimization	Performance

For commits without conventional prefixes, infer the category from the diff content:

• New files → likely a feature
• Modified test files → testing
• Config changes → maintenance
• README/docs changes → documentation

Step 3: Generate PR Description

Use this template:

## Summary

[1-3 sentences describing the overall purpose and motivation]

## Changes

### [Category 1]
- [Change description with context]
- [Change description with context]

### [Category 2]
- [Change description with context]

## Files Changed

[Number] files changed, [additions] insertions(+), [deletions] deletions(-)

Key files:
- `path/to/important/file.ts` — [what changed and why]
- `path/to/another/file.ts` — [what changed and why]

## Testing

- [ ] [Specific test action based on changes]
- [ ] [Another test action]
- [ ] [Edge case to verify]

## Notes for Reviewers

[Any context that helps reviewers: design decisions, trade-offs, areas needing extra scrutiny, migration steps, etc.]

Step 4: Present and Refine

1. Show the generated description to the user
2. Ask if they want to adjust anything (title, scope, details)
3. If creating the PR directly, use gh pr create with the description

Quality Guidelines

• Title: Under 72 characters, imperative mood ("Add feature" not "Added feature")
• Summary: Focus on WHY, not just WHAT. Link to issues if referenced in commits.
• Changes: Group by category. Each bullet should explain the change AND its purpose.
• Testing: Be specific. "Run tests" is not helpful. "Run npm test -- --grep auth" is.
• Notes: Call out anything surprising, incomplete, or that needs follow-up.

Examples

Good Title

Add rate limiting to API endpoints

Bad Title

Updated some files and fixed things and also added rate limiting and cleaned up tests

Good Change Description

- Add token bucket rate limiter to /api/auth/* endpoints (100 req/min per IP)
  to prevent brute-force attacks on login

Bad Change Description

- Updated rate-limit.ts

Edge Cases

• Single commit PR: Use the commit message as the title, expand the body
• Many small commits: Group by theme rather than listing each commit
• Merge commits: Skip merge commits in the analysis
• Draft PR: Note that it's a draft and what's still TODO
• Breaking changes: Add a prominent "Breaking Changes" section at the top