label-new-language-prs.yml

name: Auto-Label New Language PRs
on:
  pull_request:
    branches: [main]


jobs:
  compare:
    name: Compare Languages
    runs-on: ubuntu-latest
    outputs:
      should-label: ${{ steps.compare.outputs.should-label }}

    steps:
      - name: Fetch current languages.yaml
        uses: actions/checkout@v4
        with:
          path: old
          ref: ${{ github.event.pull_request.base.sha }}
          sparse-checkout: gengo/languages.yaml
          sparse-checkout-cone-mode: false
          clean: false
      - name: Fetch updated languages.yaml
        uses: actions/checkout@v4
        with:
          path: new
          ref: ${{ github.event.pull_request.head.sha }}
          sparse-checkout: gengo/languages.yaml
          sparse-checkout-cone-mode: false
          clean: false
      - name: Checkout scripts
        uses: actions/checkout@v4
        with:
          path: scripts
          sparse-checkout: scripts/
          sparse-checkout-cone-mode: false
          clean: false
      - uses: ruby/setup-ruby@v1
        with:
          ruby-version: '3.0'
      - name: Compare languages
        run: (ruby ./scripts/scripts/should-tag-new-language.rb old/gengo/languages.yaml new/gengo/languages.yaml && echo "should-label=true" || echo "should-label=false") >> "$GITHUB_OUTPUT"
        id: compare
        shell: bash

  label:
    name: Label PR
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    needs:
      - compare
    if: ${{ needs.compare.outputs.should-label == 'true' }}

    steps:
      - run: gh pr edit $PR_URL --add-label "$PR_LABEL"
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          PR_URL: ${{ github.event.pull_request.html_url }}
          PR_LABEL: new-language