label_check.yml

name: Check release label

on:
  pull_request:
    types:
      - synchronize
      - opened
      - reopened
      - labeled
      - unlabeled

jobs:
  label_check:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v2

      - name: Check labels
        run: |
          NUMBER_OF_LABELS=$(jq '.pull_request.labels | length' "$GITHUB_EVENT_PATH")
          if [ $NUMBER_OF_LABELS -eq 0 ]; then
            echo "PR has no labels. Please add at least one label of release type."
            exit 1
          fi

          RELEASE_LABELS=("release::enhancements" "release::bug_fixes" "release::ci_docs")
          PR_LABELS=$(jq -r '.pull_request.labels[].name' "$GITHUB_EVENT_PATH")
          NB_RELEASE_LABELS=0

          for LABEL in $PR_LABELS; do
            if [[ " ${RELEASE_LABELS[@]} " =~ " ${LABEL} " ]]; then
              NB_RELEASE_LABELS=$((NB_RELEASE_LABELS+1))
            fi
          done

          if [ $NB_RELEASE_LABELS -eq 0 ]; then
            echo "PR has no release labels. Please add a label of release type."
            exit 1
          elif [ $NB_RELEASE_LABELS -gt 1 ]; then
            echo "PR has multiple release labels. Please remove all but one label."
            exit 1
          fi