label-remover.yml

name: Label remover

on:
  # Run workflow when commits are added to PR or when the PR is labeled
  pull_request_target:
    types: [ synchronize, labeled ]

jobs:
  remove-label:
    runs-on: ubuntu-latest
    
    steps:
      # We remove the label when a commit is added and it has the 'safe to build' label
      - name: Remove label
        if: github.event.action == 'synchronize' && contains(github.event.pull_request.labels.*.name, 'safe to build')
        run: |
          curl --silent --fail \
          -X DELETE \
          -H 'Accept: application/vnd.github.v3+json' \
          -H 'Authorization: token ${{ github.token }}' \
          'https://api.github.com/repos/${{ github.repository }}/issues/${{ github.event.number }}/labels/safe%20to%20build'
      # Fail workflow to indicate that the PR has not been built because of new commits
      - name: Fail workflow
        if: github.event.action == 'synchronize'
        uses: actions/github-script@v3
        with:
          script: |
            core.setFailed('PR was not marked with "safe to build" label')