name: Do Not Merge

on:
  pull_request:
    types: [synchronize, opened, reopened, labeled, unlabeled]

jobs:
  do-not-merge:
    if: contains(github.event.*.labels.*.name, 'Do Not Merge')
    name: Check Do Not Merge
    runs-on: ubuntu-latest
    steps:
      - name: check for label
        run: |
          echo "Pull request is labeled as 'Do Not Merge'"
          echo "This workflow fails so that the pull request cannot be merged"
          exit 1