merge.yml

name: Merge

on:
  pull_request:

jobs:
  check_for_merge_commit:
    name: mergeable
    runs-on: ubuntu-latest
    steps:
      - name: Run git checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Check if PR has Merge Commits
        run: |
          merge=$(git log ${{github.event.pull_request.base.sha}}..${{github.event.pull_request.head.sha}} --oneline --merges)
          if [[ ! -z ${merge} ]]; then
            # PR contains merge commits
            echo "merge commit detected in pull request!"
            exit 1
          fi