label-external-contributions.yml

name: Label external contributions

on:
  schedule:
    - cron: "7,22,37,52 * * * *"
  workflow_dispatch:

permissions: {}

concurrency:
  group: label-external-contributions
  cancel-in-progress: false

jobs:
  label:
    if: github.ref_name == github.event.repository.default_branch
    runs-on: ubuntu-latest
    timeout-minutes: 10
    permissions:
      pull-requests: write

    steps:
      - name: Label external contributions
        env:
          GH_TOKEN: ${{ github.token }}
          REPO: ${{ github.repository }}
        run: |
          set -euo pipefail

          label="external-contribution"
          updated_cutoff=$(date -u -d "1 hour ago" "+%Y-%m-%dT%H:%M:%SZ")

          while IFS= read -r pr_number; do
            if [[ ! "$pr_number" =~ ^[1-9][0-9]*$ ]]; then
              echo "Skipping malformed pull request number."
              continue
            fi

            pr_json=$(gh api "repos/$REPO/pulls/$pr_number")
            if ! jq -e \
              --arg repo "$REPO" \
              --arg label "$label" \
              '.state == "open" and
               .draft == false and
               .base.repo.full_name == $repo and
               (.head.repo.full_name | type == "string") and
               .head.repo.full_name != $repo and
               .user.type == "User" and
               .author_association != "MEMBER" and
               .author_association != "OWNER" and
               (any(.labels[]?; .name == $label) | not)' \
              >/dev/null <<<"$pr_json"; then
              continue
            fi

            events=$(gh api --paginate \
              "repos/$REPO/issues/$pr_number/events?per_page=100" |
              jq -cs 'add')

            if jq -e --arg label "$label" \
              'any(.[]; .event == "labeled" and .label.name == $label)' \
              >/dev/null <<<"$events"; then
              continue
            fi

            jq -n --arg label "$label" '{labels: [$label]}' |
              gh api --method POST \
                "repos/$REPO/issues/$pr_number/labels" \
                --input - \
                >/dev/null
            echo "Labelled pull request #$pr_number."
          done < <(
            gh api --method GET --paginate "repos/$REPO/issues" \
              -f state=open \
              -f since="$updated_cutoff" \
              -f sort=updated \
              -f direction=desc \
              -f per_page=100 |
              jq -r '.[] | select(.pull_request != null) | .number'
          )