label-checker.yaml

name: Check PR Labels

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

jobs:
  check-label:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout repository
        uses: actions/checkout@v2

      - name: Set up Python
        uses: actions/setup-python@v5
        with:
          python-version: "3.12"
          cache: "pip"

      - name: Install yq
        run: |
          pip install yq

      - name: Get required labels from release.yml
        id: get-required-labels
        run: |
          labels=()
          for label in $(yq -r '.changelog.categories[] | select(.title != "Uncategorized") | .labels[]' .github/release.yml); do
            labels+=("$label")
          done

          labels_string=$(IFS=, ; echo "${labels[*]}")

          echo "Required labels: $labels_string"
          echo "required_labels=$labels_string" >> $GITHUB_OUTPUT

      - name: Get PR labels
        id: get-pr-labels
        run: |
          labels=()
          for label in $(jq -r '.pull_request.labels[].name' "$GITHUB_EVENT_PATH"); do
            labels+=("$label")
          done

          labels_string=$(IFS=, ; echo "${labels[*]}")

          echo "PR labels: $labels_string"
          echo "labels=$labels_string" >> $GITHUB_OUTPUT

      - name: Check for specific labels
        id: check-label
        run: |
          required_labels="${{ steps.get-required-labels.outputs.required_labels }}"
          pr_labels="${{ steps.get-pr-labels.outputs.labels }}"

          IFS=',' read -r -a required_labels_array <<< "$required_labels"
          IFS=',' read -r -a pr_labels_array <<< "$pr_labels"

          found=false
          for required_label in "${required_labels_array[@]}"; do
            for pr_label in "${pr_labels_array[@]}"; do
              if [[ "$required_label" == "$pr_label" ]]; then
                found=true
                break 2
              fi
            done
          done

          echo "label_exists=$found" >> $GITHUB_OUTPUT

      - name: Fail if no required labels are found
        if: steps.check-label.outputs.label_exists == 'false'
        run: |
          echo "None of the required labels are applied to the PR."
          exit 1