name: Close Non-Feature Branches

on:
  pull_request_target:
    branches:
      - master

jobs:
  close-master-branch:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    env:
      PR_NUMBER: ${{ github.event.pull_request.number }}
      GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
    steps:

      - uses: actions/checkout@v2
        with:
          fetch-depth: 0
          ref: ${{ github.event.pull_request.head.sha }}

      - name: Close if master branch
        if: ${{ github.head_ref	== 'master' }}
        run: |
          gh pr close $PR_NUMBER
          gh pr comment $PR_NUMBER --body "This pull request has been automatically closed. Please develop on a feature branch. Thank you."
          exit 1