label-sync.yml

name: Pull Request Label Sync

on:
  pull_request_target:
    types: [opened, reopened, synchronize]
  pull_request:
    types: [opened, reopened, synchronize]
  workflow_call:
    inputs:
      copy_issue_labels:
        type: boolean
        default: true
        description: "Copy labels from linked issue"

permissions:
  contents: read
  pull-requests: write

jobs:
  copy-issue-labels:
    if: inputs.copy_issue_labels == true || github.event_name != 'workflow_call'
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v6

      - name: Extract issue number from PR
        id: extract-issue
        env:
          BODY: ${{ github.event.pull_request.body }}
          TITLE: ${{ github.event.pull_request.title }}
        run: |
          ISSUE=$(echo "$TITLE $BODY" | \
            grep -oiE '(closes|fixes|resolves|addresses)\s+#[[:digit:]]+' | \
            grep -oE '#[[:digit:]]+' | head -1 | tr -d '#')

          if [ -n "$ISSUE" ]; then
            echo "issue_number=$ISSUE" >> "$GITHUB_OUTPUT"
          fi

      - name: Copy labels from issue to PR
        if: steps.extract-issue.outputs.issue_number != ''
        run: |
          LABELS=$(gh issue view "$ISSUE_NUM" --repo "$REPO" --json labels --jq '.labels[].name')

          for label in $LABELS; do
            gh pr edit "$PR_NUM" --repo "$REPO" --add-label "$label" 2>/dev/null || true
          done
        env:
          ISSUE_NUM: ${{ steps.extract-issue.outputs.issue_number }}
          PR_NUM: ${{ github.event.pull_request.number }}
          REPO: ${{ github.repository }}
          GH_TOKEN: ${{ github.token }}