babysit-pr

Babysit PR

Monitors a pull request and autonomously maintains it: fixes failed CI checks, rebases to resolve merge conflicts, and enables auto-merge. Designed for repeated invocation via /loop — each call is one check-and-fix pass.

PR Identification

Determine the target PR from (in priority order):

1. Explicit PR number or URL in the user's message
2. Current branch → gh pr view --json number,title
3. Ask the user

Workflow

Each invocation runs through these steps in order. After each push, wait for checks to complete before continuing.

1. Check PR status

gh pr view <PR> --json number,title,state,mergeable,baseRefName,headRefName,autoMergeRequest
gh pr checks <PR>

If the PR is merged or closed, report final state and stop.

2. Fix failed checks

If any checks are failing:

1. Find failed runs:

   gh run list --branch <head-branch> --status failure --limit 5 --json databaseId,name,conclusion
   

2. Read failure logs:

   gh run view <run-id> --log-failed
   

3. Diagnose the failure from the logs. Common categories:
   • Test failures: read the failing test and code under test, fix the root cause
   • Lint/format errors: run the linter/formatter locally, apply fixes
   • Type errors: fix type issues
   • Build failures: fix compilation errors
4. If the failure is ambiguous or requires design decisions, report it and ask the user instead of guessing.
5. Stage, commit, and push:

   git add <specific-files>
   git commit -m "fix(ci): <description>"
   git push
   

6. Wait for checks to complete:

   gh pr checks <PR> --watch
   

7. If checks pass, continue to step 3. If checks fail again, loop back to step 2.1 to diagnose the new failure.

3. Resolve merge conflicts

If mergeable is CONFLICTING:

1. Fetch and rebase:

   git fetch origin
   git rebase origin/<base-branch>
   

2. Resolve each conflict — preserve the feature branch's intent while incorporating base branch changes.
3. Complete the rebase:

   git add <resolved-files>
   git rebase --continue
   

4. Push safely:

   git push --force-with-lease
   

5. Wait for checks to complete:

   gh pr checks <PR> --watch
   

6. If checks fail after rebase, go to step 2 to fix them.

4. Enable auto-merge

If all checks are passing and auto-merge is not yet enabled (autoMergeRequest is null):

gh pr merge <PR> --auto --squash

5. Report

Output a single status line:

Status	Meaning
All checks passing, auto-merge enabled	Nothing to do — PR will merge when ready
Fixed <description>, checks green, auto-merge enabled	PR is ready to merge
Rebased onto <base>, checks green, auto-merge enabled	PR is ready to merge
Could not fix: <reason>	Needs user intervention

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Key Behaviors

• Wait after push: always run gh pr checks <PR> --watch after pushing, then continue the workflow based on the result.
• Safe force-push: always --force-with-lease, never --force.
• Ask when unsure: if a CI failure is ambiguous or a conflict resolution requires a judgment call, report the issue and ask the user rather than guessing.
• Idempotent: each invocation reads current PR state fresh. Safe to run on a timer via /loop. When there's nothing to do, report status and exit quickly.