pr-version-label.yml

name: PR version label

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

permissions:
  pull-requests: write

jobs:
  validate-version-label:
    runs-on: ubuntu-latest
    steps:
      - name: Default to Tag/Patch on a brand-new PR
        if: github.event.action == 'opened'
        env:
          GH_TOKEN: ${{ github.token }}
        run: |
          labels=$(gh pr view "${{ github.event.pull_request.number }}" --repo "${{ github.repository }}" --json labels --jq '.labels[].name')
          if ! grep -qE '^Tag/(Patch|Minor|Major)$' <<< "$labels"; then
            gh pr edit "${{ github.event.pull_request.number }}" --repo "${{ github.repository }}" --add-label "Tag/Patch"
          fi

      - name: Exactly one Tag/* label, or none at all
        env:
          GH_TOKEN: ${{ github.token }}
        run: |
          # Re-read labels rather than trusting the event payload -- the
          # step above may have just changed them.
          labels=$(gh pr view "${{ github.event.pull_request.number }}" --repo "${{ github.repository }}" --json labels --jq '.labels[].name')
          count=$(grep -cE '^Tag/(Patch|Minor|Major)$' <<< "$labels" || true)
          echo "Tag/* labels present: $count"
          if [ "$count" -gt 1 ]; then
            echo "::error::More than one Tag/Patch, Tag/Minor, Tag/Major label is present -- pick exactly one, or remove all of them to skip versioning this PR."
            exit 1
          fi