Gh Pr

GitHub PR Communication Skill

Use this skill for creating, updating, or commenting on GitHub pull requests. Focus on material impact, safe operations, and respecting busy reviewers.

When to Use This Skill

• Creating PRs from feature branches
• Updating PR descriptions after significant changes
• Adding comments to communicate with reviewers
• Any PR communication task

Announcement

Always announce at start:

"I'm using the gh-pr skill to <create|update|comment on> the pull request."

Core Principles

1. Safety first: All PR bodies written to .scratch/pr-bodies/ before use with gh --body-file
2. Material impact: Focus on why changes matter, not metrics or file counts
3. Smart merge: Detect manual edits, only update when changes are material
4. Human-friendly: Concise, warm tone; assume busy reviewer
5. Flexible workflow: Explicit commands when clear, smart routing when ambiguous

File Structure

.scratch/pr-bodies/
  drafts/
    <slugified-title>.md          # Draft body before PR creation
  <pr-number>/
    metadata.json                  # PR metadata and state
    <timestamp>-body.md           # Timestamped snapshots of generated bodies
    <timestamp>-comment.md        # Comment drafts

Metadata Schema

{
  "pr_number": 123,
  "branch": "feature/add-skill",
  "base": "main",
  "title": "Add spotlight exclusion skill",
  "created_at": "2025-11-07T10:30:00Z",
  "last_generated_hash": "abc123def456",
  "last_updated_at": "2025-11-07T16:45:30Z",
  "manual_edits_detected": false
}

Trigger Patterns

Explicit Triggers (Always Honored)

• "create a PR" / "open a PR" → Create flow
• "update the PR body/description" → Update body flow
• "comment on the PR" / "add a PR comment" → Comment flow

Ambiguous Triggers (Smart Routing)

"update the PR":

• No PR exists → Error: "No PR found for this branch. Did you mean to create one?"
• PR exists, no reviews → Update body
• PR exists, has reviews → Ask: "This PR has reviews. Update body or add comment?"

"communicate the changes":

• PR exists, no reviews yet → Update body
• PR exists, has reviews → Add comment (generates notifications)

Operation Flows

1. Create PR

☐ Check if PR already exists
  - gh pr view --json number 2>/dev/null
  - If exists → error or route to update

☐ Gather information
  - Commits: git log <base>..HEAD
  - Check for PR template (.github/pull_request_template.md, etc.)
  - Check for CONTRIBUTING.md
  - Analyze commit messages and diffs

☐ Generate PR content
  - Title: from branch name or first commit (imperative mood, <72 chars)
  - Body:
    * Follow template structure if exists
    * Summary: 2-4 bullets of material impact
    * Test plan: if non-obvious
    * NO H1 heading (GitHub shows title separately)
    * NO metrics (# tests, # files, etc.)
    * Concise, warm tone

☐ Draft review
  - Write to .scratch/pr-bodies/drafts/<slug>.md
  - Show draft to user: "Here's the draft PR. Does this look good?"
  - Allow edits before creating

☐ Create PR
  - gh pr create --title "..." --body-file .scratch/pr-bodies/drafts/<slug>.md
  - Capture PR number from output

☐ Archive and track
  - mkdir -p .scratch/pr-bodies/<number>/
  - mv draft to <number>/<timestamp>-body.md
  - Write metadata.json with hash of generated body
  - rm .scratch/pr-bodies/drafts/<slug>.md

2. Update PR Body

☐ Verify PR exists
  - gh pr view --json number,body,title,state
  - Load metadata.json if exists
  - Check state (error if closed/merged unless user confirms)

☐ Detect manual edits
  - Hash current body: echo "$body" | shasum -a 256
  - Compare to last_generated_hash in metadata
  - If differs:
    * Compute diff: diff <(echo "$last_generated") <(echo "$current")
    * Analyze: whitespace-only vs content changes
    * If material: show diff, ask "Overwrite manual edits, merge, or cancel?"

☐ Check for material changes
  - Re-analyze full commit range: <base>..HEAD
  - Compare to previous analysis
  - If no material change:
    * "The current PR description is still accurate."
    * Skip update unless user forces

☐ Generate updated body
  - Follow same content guidelines as create
  - Re-analyze all commits in range

☐ Draft review
  - Write to .scratch/pr-bodies/<number>/<timestamp>-body.md
  - Show diff: current vs proposed
  - "Here's what would change. Look good?"

☐ Update PR
  - gh pr edit <number> --body-file <file>
  - Update metadata.json (hash, timestamp, manual_edits_detected)

3. Add PR Comment

☐ Verify PR exists
  - gh pr view --json number,title,reviews,comments
  - Check for review activity

☐ Determine comment content
  - Analyze recent commits since last update
  - Focus on: what changed and why
  - Common scenarios:
    * Responding to review feedback
    * Noting significant additions after initial review
    * Summarizing a batch of changes

☐ Draft comment
  - Write to .scratch/pr-bodies/<number>/<timestamp>-comment.md
  - Tone: conversational, helpful, concise (3-5 sentences)
  - Structure: "I've updated the PR to address..."
  - Show draft to user

☐ Post comment
  - gh pr comment <number> --body-file <file>
  - Optional: Update metadata.json with comment timestamp

Decision Matrix: Update Body vs Comment

Prefer UPDATE BODY when:

• PR has no reviews/comments yet
• User explicitly says "update description/body"
• Material scope change that needs description rewrite

Prefer COMMENT when:

• PR has review activity (comments, requested changes)
• User mentions "responding to feedback"
• Batch of changes after initial review
• Want to notify watchers (comments generate notifications, body updates don't)

Content Guidelines

PR Title Format

• Imperative mood: "Add", "Fix", "Update", "Refactor"
• Concise: < 72 characters ideal
• Capitalize first word
• No period at end
• Derive from: Branch name (if semantic) or first commit message

PR Body Structure

When PR template exists:

• Follow template structure exactly
• Fill sections based on commit analysis
• Preserve template comments/instructions

When no template exists:

## Summary

- Material impact point 1
- Material impact point 2
- Material impact point 3 (if needed)

## Test plan

- How to verify the changes work
- Only if non-obvious or requires manual testing

[Optional sections based on context:]

## Breaking changes

## Migration notes

## Follow-up work

Content Principles

✅ DO:

• Focus on material impact: "Enables pattern-based Spotlight exclusions for easier maintenance"
• Be concise yet warm: "This makes it easier to manage exclusions at scale."
• Explain why it matters, what problem it solves
• Include non-obvious testing steps

❌ DON'T - Common Anti-Patterns:

Metrics (unless PR is specifically about them):

• ❌ "Added 15 tests" → ✅ "Added test coverage for edge cases"
• ❌ "Modified 8 files across 3 modules" → ✅ Say nothing (diff shows this)
• ❌ "Reduced runtime from 2.5s to 1.2s" → ✅ Only if PR is about performance
• ❌ "Added 250 lines of code" → ✅ Never mention line counts
• ❌ "Test coverage increased to 85%" → ✅ Only if PR is about coverage

Implementation details visible in diff:

• ❌ "Created new PatternExpander class" → ✅ Say nothing (diff shows this)
• ❌ "Refactored into smaller functions" → ✅ Say nothing unless it's the PR's focus
• ❌ "Used async/await pattern" → ✅ Say nothing (implementation detail)
• ❌ "Added error handling" → ✅ Only if error handling is the PR's focus

Over-explaining/verbose:

• ❌ "This change significantly improves the developer experience by implementing a novel approach..."
• ✅ "Makes it easier to maintain exclusions at scale"
• ❌ "After careful consideration of multiple approaches, we decided to..."
• ✅ Just describe what it does and why it matters

Other common mistakes:

• ❌ Use H1 heading (GitHub shows title separately, causes duplication)
• ❌ List technologies used unless it's a new dependency worth noting
• ❌ Describe file structure changes unless it's an architectural shift
• ❌ Mention "following best practices" (assumed)
• ❌ Say "easy to" or "simple to" (condescending)

The rule: If a reviewer can see it in the diff or CI output, don't put it in the PR body unless it's the central focus of the PR.

Following Repository Guidelines

Search for PR templates:

- .github/pull_request_template.md
- .github/PULL_REQUEST_TEMPLATE.md
- .github/PULL_REQUEST_TEMPLATE/*.md

Search for CONTRIBUTING.md:

- CONTRIBUTING.md
- .github/CONTRIBUTING.md
- docs/CONTRIBUTING.md

If found: Extract PR-related guidance (required info, checklists, style) and incorporate into body generation.

Comment Content Guidelines

Structure:

I've updated the PR to address the feedback:

- Point about what changed
- Another significant change
- Why these changes were made

[Optional: specific response to review comment if relevant]

Tone:

• Conversational but professional
• Acknowledge reviewers' input
• Explain reasoning when non-obvious
• Keep brief (3-5 sentences typical)

Error Handling & Edge Cases

Safety Checks

Before creating PR:

• ✓ Current branch is not main/master
• ✓ Branch has commits ahead of base
• ✓ gh CLI is installed and authenticated
• ✓ User has reviewed draft

Before updating PR body:

• ✓ PR exists and is open (warn if closed/merged)
• ✓ Manual edits check complete
• ✓ User has reviewed diff

Before posting comment:

• ✓ PR exists
• ✓ Comment is not empty
• ✓ User has reviewed content

Common Errors

No PR exists (when updating/commenting):

Error: "No PR found for branch '<branch-name>'.
Would you like to create one?"

Action: Offer to route to create flow

Multiple PRs for branch:

1. gh pr list --head <branch> --state open
2. If exactly 1 open PR → use it
3. If 0 open PRs:
   - Check: gh pr list --head <branch> --state all
   - "No open PR found. Last PR was #123 (closed/merged)."
   - Offer to create new PR
4. If >1 open PR (rare):
   - "Found multiple open PRs: #123, #456. Which one?"

Not on a branch / on main:

Error: "Currently on '<branch>'.
PRs should be created from feature branches, not main/master."

Action: Stop, suggest creating a branch first

gh CLI not available:

Error: "GitHub CLI (gh) not found. Install with: brew install gh"

gh not authenticated:

Error: "GitHub CLI not authenticated. Run: gh auth login"

Edge Cases

Manual edits detected:

1. Show diff: "The PR body has been manually edited. Here's what changed:"
2. Ask: "Overwrite manual edits, merge, or cancel?"
   - Overwrite: Replace with new generated body
   - Merge: Preserve manually-added sections
   - Cancel: Keep current body

No material changes in update:

"Analyzed commits - no material changes to scope or impact.
The current PR description is still accurate."

Action: Skip update unless user forces

Draft in progress:

"Found existing draft for '<title>'.
Use existing draft, create new, or cancel?"

Scratch directory doesn't exist:

mkdir -p .scratch/pr-bodies/drafts

Change Detection Algorithm

# 1. Quick hash check
current_hash=$(gh pr view body -q .body < number > --json | shasum -a 256)
last_hash=$(jq -r .last_generated_hash .scratch/pr-bodies/ < number > /metadata.json)

# 2. If hashes match → no changes
if [ "$current_hash" = "$last_hash" ]; then
  echo "No manual edits detected"
  exit 0
fi

# 3. If hashes differ → compute diff
gh pr view body -q .body < number > --json > /tmp/current.md
cat .scratch/pr-bodies/ < number > / < last-timestamp > -body.md > /tmp/last.md
diff -u /tmp/last.md /tmp/current.md

# 4. Analyze diff
# - Whitespace only? → Not material
# - Content changes? → Material, set manual_edits_detected = true

Integration with Other Skills

working-in-scratch-areas:

• All drafts go to .scratch/pr-bodies/
• Auto-creates directory structure

git-preferences-and-practices:

• Respects git workflow preferences
• Works with branch naming conventions

Repository conventions:

• Checks for ADRs and references them
• Links to docs/plans if design doc exists

Example Workflows

Creating a PR

User: "create a PR for this branch"

Claude: "I'm using the gh-pr skill to create the pull request."
[Analyzes commits: 5 commits adding spotlight exclusion patterns]
[Checks for templates: none found]
[Generates draft in .scratch/pr-bodies/drafts/add-spotlight-patterns.md]

Claude: "Here's the draft PR. The summary focuses on the pattern-based
approach and easier maintenance. Does this look good?"

[Shows draft content]

User: "yes"

Claude: [Creates PR #123]
"Created PR #123: Add spotlight exclusion patterns
https://github.com/user/repo/pull/123"

Updating After Changes

User: "update the PR"

Claude: "I'm using the gh-pr skill to update the pull request."
[Checks PR #123]
[Hash check: no manual edits]
[Analyzes commits: 3 new commits adding monitoring tools]

Claude: "I've added 3 commits since the PR was created. The scope has
expanded to include monitoring tools. Should I update the description?"

User: "yes"

Claude: [Generates new body]
"Here's what would change in the description:

+ ## Monitoring
+ Includes live monitoring and activity analysis tools

Look good?"

User: "yes"

Claude: [Updates PR]
"Updated PR #123 description"

Adding a Comment

User: "comment on the PR about the changes"

Claude: "I'm using the gh-pr skill to comment on the pull request."
[Checks PR #123: has 2 review comments]

Claude: "This PR has review comments. I'll add a comment about the
recent updates. Here's the draft:

---
I've updated the PR to address the feedback:
- Added input validation for pattern file paths
- Improved error messages for invalid patterns
- Updated tests to cover edge cases

The validation now catches malformed patterns before attempting expansion.
---

Look good?"

User: "yes"

Claude: [Posts comment]
"Added comment to PR #123"

File Management

Keep:

• metadata.json (permanent record)
• Last 5 timestamped bodies/comments
• Current draft (if in progress)

Clean up:

• Completed drafts after PR creation
• Old timestamped files (optional: >30 days)

Implementation Notes

Hash algorithm: Use shasum -a 256 for consistency

Timestamp format: ISO 8601 with hyphens for filenames: 2025-11-07T10-30-00

Slugification: Lowercase, hyphens, strip special chars: "Add Spotlight Skill" → "add-spotlight-skill"

Base branch detection:

# Try to detect from gh pr view first
base=$(gh pr view --json baseRefName -q .baseRefName 2> /dev/null)

# Fall back to common defaults
if [ -z "$base" ]; then
  if git show-ref --verify --quiet refs/heads/main; then
    base="main"
  else
    base="master"
  fi
fi