PR review auto (Hangar, GitHub)

Invoking this skill authorizes, for the named PR only: fixing code on the PR branch, committing, pushing to that branch, replying to and resolving CodeRabbit threads, and merging when ready when §5 allows it. It does not authorize: force push, rebase, --admin outside §5, closing the PR, pushing to main, deleting the branch. CodeRabbit already reviews on GitHub: never run the coderabbit CLI.

SKILL_DIR is this skill's base directory. <repo> is gh repo view --json nameWithOwner -q .nameWithOwner run in the PR's tree; <main tree> is the first line of git worktree list. All user-facing text in the user's language.

1. Pick the PR and the tree

1. PR number from the request; none → gh pr view --json number,headRefName on the current branch.
2. gh pr view <N> --json headRefName,author,isCrossRepository,maintainerCanModify,state.
3. Find the tree holding the branch: git worktree list.
   • It is this session's cwd → work here.
   • Another live session's cwd (hangar-send --list) → hand over: hangar-send <session> "Rode a skill pr-review-auto no PR #<N>.", tell the user who got it, and stop.
   • No checkout → ask the user where to check it out (never create a worktree or switch the shared main tree on your own).
   • Cross-repo PR without maintainerCanModify → you cannot push: handle threads by reply only and report what the author must change.
4. git status in that tree: someone else's dirty files stay out of every commit.

2. Watch

Start the Monitor tool with timeout_ms: 1800000:

python3 -u "SKILL_DIR/scripts/pr_watch.py" <N>

It polls GitHub every 60 s and prints only lines worth acting on. State is saved in ~/.cache/hangar-pr-watch/, so re-arming does not repeat events; --reset replays the current snapshot. --once prints the snapshot (with ready) and exits — use it for checks, not loops.

On {"control":"window_ended"} or the Monitor expiry notice, re-arm the same command silently. On {"control":"expired"} (24 h) tell the user and stop. Keep exactly one Monitor per PR.

After arming, end the turn. No sleeps, no CronCreate, no periodic status messages.

3. Events

A change carries the full snapshot. Handle, in this order:

• threads whose last_by is not you: read the whole thread (gh api repos/<repo>/pulls/<N>/comments or the url), check it against the current code. Fix every valid point, small ones included. Reject only what is factually wrong or out of scope, with one reply in the thread, @coderabbitai + evidence, then resolve it (an unresolved thread blocks ready forever).
• replies_in_resolved_threads: CodeRabbit answered in a thread already resolved. Agreement needs nothing; a new objection is treated like an open thread.
• reviews_on_head with nitpicks: true: read the review body (gh api repos/<repo>/pulls/<N>/reviews/<id>) and treat each nitpick the same way. Skipped nitpicks get one top-level @coderabbitai comment saying which and why.
• bot_comments that answer you: read; a new technical objection needs analysis, agreement needs nothing.
• coderabbit: "NEUTRAL" (it concluded without reviewing this head, usually its rate limit): run the code-review skill once on the PR (high <N>; a harness without it runs the stack reviewer on gh pr diff <N>). Fix every valid finding (§4), log the rest, then python3 SKILL_DIR/scripts/pr_watch.py <N> --mark-local-review <head of the last push>. A head that only adds those fixes is marked without another review.
• failed checks: gh run view <run> --log-failed. Caused by the PR → fix. Known flaky or infra (runner, network) → gh run rerun <run> --failed once; fails again → report and stop. Unrelated to the PR and not flaky → report and stop; do not merge.
• mergeable: CONFLICTING: git merge origin/main into the branch (never rebase), resolve, commit.
• Pending CI only, or a new head you just pushed: nothing to do.

Keep a log at ~/.cache/hangar-pr-watch/<owner>_<name>_<N>.log.md: thread/review id, decision, fix commit, reply sent. Read it after a context compaction; never reply twice to the same point.

4. Publish a round

1. Stage by explicit path, only this round's files. Descriptive English message (fix(scope): …), never the branch name.
2. Push to the PR branch. The review hook blocks the first push: run the stack reviewer once on the round's diff, apply what holds, push again — fixes from the reviewer are not reviewed again. Push with HANGAR_SEM_VERIFICACAO=1 git push (the maintainer's choice for this skill): do not run scripts/verificar-local; the PR's CI is the gate, and §5 only merges on green CI.
3. For each fixed thread reply once: gh api repos/<repo>/pulls/<N>/comments/<root_comment_id>/replies -f body="@coderabbitai Corrigido em <sha>. <what changed>." then resolve it: gh api graphql -f query='mutation($t:ID!){resolveReviewThread(input:{threadId:$t}){thread{isResolved}}}' -F t=<thread_id>. A later bot reply in that thread arrives in replies_in_resolved_threads.

5. Ready → merge

ready means: PR open, not draft, mergeable, CodeRabbit status SUCCESS on the head (or NEUTRAL with the local review marked for it), no unresolved thread, every check terminal and none failed, unchanged for 90 s. The script does not know about nitpicks: confirm every nitpick in the log was handled. Your own notes never wake you, including ones the user wrote by hand under the same GitHub account.

1. python3 SKILL_DIR/scripts/pr_watch.py <N> --once → ready: true and the same head. Otherwise keep watching.
2. main requires one approval, and nobody else approves: only an admin merges, bypassing it. viewer_permission not ADMIN (WRITE, MAINTAIN, …) → do not merge: stop the Monitor, tell the user the PR is ready and waits for an admin's approval or merge, and stop.
3. ADMIN → gh pr merge <N> --merge --admin --match-head-commit <head> (merge commit, the repo's convention; keep the branch). The head check refuses the merge if someone pushed after step 1.
4. Stop the Monitor with TaskStop.
5. Align the shared checkout: in <main tree>, on main with a clean tree, git fetch origin && git merge --ff-only origin/main. Not fast-forward or dirty → just say so.
6. Report: PR, merge commit, what was fixed vs. answered, the main CI run (gh run list --branch main -L 1).

User says stop → TaskStop, no resume.