merge_queue.yml

name: Merge Queue Tests
on:
  merge_group:
  push:
  pull_request:

jobs:
  verify_merge:
    name: Verify map merge sanity
    runs-on: ubuntu-latest
    # Below if lets it run as a required check but skip on normal push/PR events
    if: ${{ github.event_name == 'merge_group'}}
    env:
      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
    steps:
      - name: Checkout code
        uses: actions/checkout@v4
        with:
          # allegedly this is as deep as necessary to always receive the base ref
          fetch-depth: 2

      - name: Verify map merge
        run: |
          # assume we're at the head ref and give it a name we know
          git switch -c gh/mergequeue/head
          # go back to the base ref and attempt our own merge
          git checkout ${{ github.event.merge_group.base_sha }}
          git switch -c gh/mergequeue/base
          git merge gh/mergequeue/head

          # the merge was not concluded cleanly
          if [ -e ".git/MERGE_HEAD" ]; then
            echo "Merge state detected; manual resolution most likely required"
            exit 1
          fi

          # if our merge was clean but our's and GitHubs differ, then complain
          if [[ `git diff --exit-code gh/mergequeue/head` ]]; then
            echo "Queue merge does not match driver merge; manual resolution most likely required"
            exit 1
          fi