pr-research

SKILL.md

PR Research Skill

Systematic exploration of upstream repositories before contributing.

Overview

Research an external codebase to understand how to contribute effectively.
This is the FIRST step before planning or implementing an open source contribution.

When to Use:

Before contributing to an external repository

Starting a new open source contribution

Evaluating whether to contribute to a project

When NOT to Use:

Researching your own codebase (use $research)

Already familiar with the project's guidelines

Workflow

-1. Prior Work Check    -> BLOCKING: Check for existing issues/PRs
0.  CONTRIBUTING.md     -> MANDATORY: Find contribution guidelines
1.  Repository Setup    -> Clone/identify upstream repo
2.  Guidelines Analysis -> Templates, CODE_OF_CONDUCT
3.  PR Archaeology      -> Analyze merged PRs, commit patterns
4.  Maintainer Research -> Response patterns, review expectations
5.  Issue Discovery     -> Find contribution opportunities
6.  Output              -> Write research document

Phase -1: Prior Work Check (BLOCKING)

CRITICAL: Before ANY research, check if someone is already working on this.

# Search for open issues on this topic
gh issue list -R <owner/repo> --state open --search "<topic keywords>" --limit 20

# Search for open PRs that might address this
gh pr list -R <owner/repo> --state open --search "<topic keywords>" --limit 20

# Check for recently merged PRs (might already be fixed)
gh pr list -R <owner/repo> --state merged --search "<topic keywords>" --limit 10

Finding
Action

Open issue exists
Link to it, don't create duplicate

Open PR exists
Don't duplicate work

Recently merged PR
Verify fix, no work needed

No prior work found
Proceed to Phase 0

Phase 0: CONTRIBUTING.md Discovery (BLOCKING)

CRITICAL: Do not proceed without finding contribution guidelines.

# Check all common locations
cat CONTRIBUTING.md 2>/dev/null
cat .github/CONTRIBUTING.md 2>/dev/null
cat docs/CONTRIBUTING.md 2>/dev/null

# Check README for contribution section
grep -i "contribut" README.md | head -10

Extract Key Requirements

Requirement
Where to Find

Commit format
"Commit messages" section

PR process
"Pull Requests" section

Testing requirements
"Testing" section

Code style
"Style" section

CLA/DCO
"Legal" or "License" section

Phase 3: PR Archaeology

CRITICAL: Understand what successful PRs look like.

# List recent merged PRs
gh pr list --state merged --limit 20

# Recent commit style
git log --oneline -30 | head -20

# Check for conventional commits
git log --oneline -30 | grep -E "^[a-f0-9]+ (feat|fix|docs|refactor|test|chore)(\(.*\))?:"

PR Size Analysis

Size
Files
Lines
Likelihood

Small
1-3
<100
High acceptance

Medium
4-10
100-500
Moderate

Large
10+
500+
Needs discussion first

Phase 5: Issue Discovery

# Find beginner-friendly issues
gh issue list --label "good first issue" --state open
gh issue list --label "help wanted" --state open

# Issues with no assignee
gh issue list --state open --json assignees,title,number | \
  jq -r '.[] | select(.assignees | length == 0) | "#\(.number): \(.title)"' | head -10

Output

Write to .agents/research/YYYY-MM-DD-pr-{repo-slug}.md

# PR Research: {repo-name}

## Executive Summary
{2-3 sentences: project health, contribution friendliness}

## Contribution Guidelines
| Document | Status | Key Requirements |
|----------|--------|------------------|
| CONTRIBUTING.md | Present/Missing | {summary} |
| PR Template | Present/Missing | {required sections} |

## PR Patterns
- **Average size**: X files, Y lines
- **Commit style**: {conventional/imperative/etc}
- **Review time**: ~X days

## Contribution Opportunities
| Issue | Type | Difficulty |
|-------|------|------------|
| #N | bug/feat | easy/medium |

## Next Steps
-> `$pr-plan .agents/research/YYYY-MM-DD-pr-{repo}.md`

Anti-Patterns

DON'T
DO INSTEAD

Skip guidelines check
Always read CONTRIBUTING.md first

Ignore PR patterns
Study successful merged PRs

Start with large PRs
Begin with small, focused changes

Workflow Integration

$pr-research <repo> -> $pr-plan <research> -> implement -> $pr-prep

Examples

Research Upstream Before Contributing

User says: "Do PR research for owner/repo before I propose a fix."

What happens:

Inspect contribution guidelines and governance files.

Analyze merged PR patterns and conventions.

Produce a research artifact with opportunities and risks.

Scope Discovery

User says: "Find small starter contribution options in this repo."

What happens:

Scan issues/labels and prior merged work.

Classify candidates by difficulty and scope.

Recommend a smallest-safe starting contribution.

Troubleshooting

Problem
Cause
Solution

No contribution guide found
Repo lacks standard files
Infer conventions from merged PR history and maintainers' comments

Too many possible issues
Scope not constrained
Filter by labels, component paths, and recent maintainer activity

Suggested work seems risky
Hidden dependency or broad blast radius
Downscope to narrower file/domain boundary and restate assumptions

Output is too generic
Insufficient repository evidence
Add concrete file/PR references and explicit pattern findings

Reference Documents

references/upstream-research-checklist.md