review-pr-diff

name	review-pr-diff
description	Review a pull request's diff and post the review. Use when MODE=review — a PR was opened or updated and you must read its diff against the base branch, find real bugs, and post a review with gh.

Review PR Diff (MODE=review)

You are reviewing PR #$PR_NUMBER on $GITHUB_REPOSITORY: head $HEAD_REF against base $BASE_REF.

Steps

1. Get the diff (base..head, so you see only what this PR changes):

   git -C /repo fetch origin "$BASE_REF" "$HEAD_REF"
   git -C /repo diff "origin/$BASE_REF...origin/$HEAD_REF"
   

   If that range is empty, fall back to git -C /repo diff "origin/$BASE_REF" HEAD.

2. Read what you need. For any changed line whose correctness depends on code not in the diff, cat /repo/<file> to see it. Do not judge from the hunk alone when context matters.

3. Find real findings per the review-discipline rule: correctness → security → broken contracts. Each finding = path:line + the concrete failure (input → wrong output/crash). Drop anything you can't trace to an exact symptom.

4. Post the review with gh. Approve if clean; request changes if there are real correctness/security findings; otherwise comment:

   gh pr review "$PR_NUMBER" --repo "$GITHUB_REPOSITORY" \
     --comment --body "$(review markdown here)"
   # or --approve (clean) / --request-changes (real blocking findings)
   

   Write the body as a short summary line, then a bulleted list of findings, each - \path:line` — `. If clean: one line, "No issues found — approving."

5. Say DONE.

You do NOT modify code, push, or open PRs in this mode (see git-safety). Read + review + post only.