check-reference.yml

name: Check patch references

on:
  push:
    branches-ignore:
      - dependabot/**
  schedule:
    # Once every day at midnight UTC
    - cron: "0 0 * * *"

jobs:
  stale:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout patches
        uses: actions/checkout@v4

      - name: Checkout core
        uses: actions/checkout@v4
        with:
          repository: 'homebrew/homebrew-core'
          path: homebrew-core

      - name: Configure Git user
        uses: Homebrew/actions/git-user-config@master
        with:
          username: BrewTestBot

      - name: Detect references
        run: |
          core_patches=$(git -C homebrew-core grep -h "Homebrew/formula-patches" | awk -F/ '{print $(NF-1)"/"$NF}' | tr -d '"')
          all_patches=$(git ls-files -- '*/*' ':^.*/*')

          git checkout -b remove-unused-patches

          for patch in $all_patches; do
            if ! grep -qx "$core_patches" <<< "$patch"; then
              echo "Unused patch: $patch; deleting."
              git rm "$patch"
              git commit -m "${patch%%/*}: remove unused ${patch#*/}"
            fi
          done

          git push origin remove-unused-patches