shared-check-pr-labels-with-prefix.yml

name: check-pr-labels-with-prefix

on:
    workflow_call:
        inputs:
            labels:
                description: "JSON string of labels from the pull request"
                required: false
                type: string
                default: ${{ toJSON(github.event.pull_request.labels) }}
            prefix:
                description: 'Label prefix to filter (e.g., "deploy-", "test-", "run-")'
                required: false
                default: ""
                type: string
        outputs:
            labels:
                description: "JSON object with labels matching the prefix"
                value: ${{ jobs.check-pr-labels-with-prefix.outputs.labels }}

jobs:
    check-pr-labels-with-prefix:
        runs-on: ubuntu-latest
        # Example outputs:
        # - With prefix "deploy-": {"deploy-d": {full label object}, "deploy-n1": {full label object}}
        outputs:
            labels: ${{ steps.filter.outputs.filtered-labels }}
        steps:
            - name: filter-labels-by-prefix
              id: filter
              env:
                  LABELS_JSON: ${{ inputs.labels }}
              run: |
                  PREFIX="${{ inputs.prefix }}"

                  echo "Prefix: $PREFIX"
                  echo "Input labels: $LABELS_JSON"

                  # Use jq to filter labels by prefix (empty prefix returns all labels)
                  JSON_RESULT=$(echo "$LABELS_JSON" | \
                    jq --arg prefix "$PREFIX" \
                    'map(select(.name | startswith($prefix))) |
                     map({(.name): .}) |
                     reduce .[] as $item ({}; . + $item)')

                  # Ensure JSON_RESULT is never empty - default to {} if empty
                  if [ -z "$JSON_RESULT" ] || [ "$JSON_RESULT" = "null" ]; then
                    JSON_RESULT="{}"
                  fi

                  # Use <<< to pass the JSON as a single line to avoid file command issues
                  {
                    echo "filtered-labels<<EOF"
                    echo "$JSON_RESULT"
                    echo "EOF"
                  } >> $GITHUB_OUTPUT

            - name: display-filter-result
              run: |
                  echo "Filtered labels: ${{ steps.filter.outputs.filtered-labels }}"