cleanup-closed-prs.yaml

name: Cleanup closed PRs
on:
  pull_request:
    types:
      - closed

jobs:
  # Based on https://github.com/actions/cache/blob/v4.2.0/tips-and-workarounds.md#force-deletion-of-caches-overriding-default-cache-eviction-policy
  actions-caches:
    name: Delete GitHub Action caches
    runs-on: ubuntu-latest
    permissions:
      # `actions:write` permission is required to delete caches
      #   See also: https://docs.github.com/en/rest/actions/cache?apiVersion=2022-11-28#delete-a-github-actions-cache-for-a-repository-using-a-cache-id
      actions: write
      contents: read

    steps:
      - name: Cleanup
        env:
          GH_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
          GH_REPO: "${{ github.repository }}"
          BRANCH: "refs/pull/${{ github.event.pull_request.number }}/merge"
        run: |
          set -euo pipefail
          gh api -X GET /repos/{owner}/{repo}/actions/caches -f ref="$BRANCH" --paginate -q '.actions_caches[] | "\(.id) \(.key)"' | {
            fail=0
            while read -r id key; do
              echo Deleting cache with ID $id: $key
              gh api -X DELETE /repos/{owner}/{repo}/actions/caches/"$id" || fail=1
            done
            [ $fail -eq 0 ]
          }