github-pr-body

name	github-pr-body
description	Update PR body content with deterministic baseline sections and optional full-body completion. Use when creating PRs or regenerating template-driven summaries.
license	Apache-2.0
metadata	{"author":"y-miyazaki","version":"1.0.1"}

Input

• PR number and owner/repo (required)
• Existing PR template/body context (required)
• Authenticated gh environment (required)

Output Specification

Return structured Markdown in accordance with references/common-output-format.md.

Structured PR output:

• Baseline mode: update ## Overview and ## Changes.
• Full-body mode: apply complete body via --body-file.
• ## Changes must classify files (Config/Docs/Feature/Test/Other) with line counts.
• Report selected mode and reason.

Execution Scope

• Always use scripts/pr_body.sh or scripts/pr_fetch.sh. Do not run individual gh commands.
• pr_body.sh is deterministic and idempotent.

USE FOR:

• generate deterministic baseline PR body sections
• regenerate PR body from template sections after code updates
• fill remaining sections in full-body mode from validated context

DO NOT USE FOR:

• post review comments or resolve review threads
• create commits or modify source files
• replace issue triage workflows

Reference Files Guide

• common-checklist.md (always read)
• common-output-format.md (always read)
• common-troubleshooting.md (read on failure)
• category-change-classification.md (always read)
• category-pr-body-guidelines.md (always read)
• category-agent-workflows.md (always read)
• category-implementation-details.md (always read)

Workflow

1. Fetch PR metadata:

   scripts/pr_fetch.sh <PR_NUMBER> --repo <OWNER/REPO>
   

   Parse JSON output to obtain: title, body, file list, additions/deletions, headRefName, baseRefName.

2. Generate deterministic baseline (## Overview, ## Changes):

   scripts/pr_body.sh <PR_NUMBER> --repo <OWNER/REPO> --dry-run
   

   Review dry-run output. If acceptable, apply:

   scripts/pr_body.sh <PR_NUMBER> --repo <OWNER/REPO>
   

3. Select mode:

   • Baseline mode: request scope is summary refresh only → skip to Step 6.
   • Full-body mode: request explicitly asks to populate all template sections → continue to Step 4.

4. Generate AI-completed content (full-body mode only):

   1. Read .github/PULL_REQUEST_TEMPLATE.md from the repository.
   2. For each H2 section in the template:
      • If the section comment contains an Example: block, follow that structure to generate visible content.
      • If the section comment contains checkbox guidance, generate or update checkbox lines in the same format.
      • If the section has no guidance, preserve the section heading and template comment without inventing content.
   3. Keep ## Overview and ## Changes content from Step 2 output.
   4. Write the complete PR body (all sections) to a temporary file (e.g., /tmp/completed_pr_body.md).

5. Apply full body (full-body mode only):

   scripts/pr_body.sh <PR_NUMBER> --repo <OWNER/REPO> --body-file /tmp/completed_pr_body.md
   

6. Verify success:

   gh pr view <PR_NUMBER> --repo <OWNER/REPO> --json body --jq '.body'
   

   Confirm ## Overview and ## Changes sections are present and non-empty. In full-body mode, confirm ## Testing, ## Type of Change, ## Checklist, and ## Additional Notes contain visible content.

Error Handling

Condition	Severity	Action
gh not authenticated	Fatal	Stop; instruct gh auth login
PR not found (404)	Fatal	Verify PR number and owner/repo
Access denied (403)	Fatal	Verify repo write scope
pr_fetch.sh or pr_body.sh missing	Fatal	Stop; report missing script
.github/PULL_REQUEST_TEMPLATE.md missing	Recoverable	Baseline mode only; skip full-body template sections
Body exceeds GitHub size limit (422)	Recoverable	Truncate or split content; report in output
Rate limit exceeded (429)	Recoverable	Defer update; note retry window in report
Dry-run output unacceptable	Info	Do not apply; report diff issues and stop

Examples

• Prompt: Generate PR body for PR #42 in owner/repo
• Result: PR description populated with Overview, Changes, Testing, and Checklist sections from diff analysis.