request_codeowners_review.yml

---
name: Request Code Owners Review

on:
  pull_request:
    types: ["opened", "synchronize"]

jobs:
  auto_request_review:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v4
        with:
          fetch-depth: ${{ github.event.pull_request.commits + 1 }}

      - name: Auto request review
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          reviewers=""
          # Get changed files in this pull request
          echo "Checking base: ${{ github.event.pull_request.base.sha }}"
          echo "Checking head: ${{ github.event.pull_request.head.sha }}"
          for changed_file in $(git diff --name-only ${{ github.event.pull_request.base.sha }} ${{ github.event.pull_request.head.sha }}); do
            echo "Checking $changed_file"
            while read -r line; do
              # Get pattern of the files owned
              pattern=$(echo "$line" | awk '{print $1}')
              # Remove leading / from pattern and changed_file for comparison
              pattern="${pattern#/}"
              # Get owners of the files owned
              owners=$(echo "$line" | awk '{$1=""; print $0}' | xargs)
              # Remove leading / from changed_file for comparison
              changed_file="${changed_file#/}"
              if [[ "$changed_file" == $pattern* ]]; then
                # Add owners to reviewers
                echo "Found owners for $changed_file: $owners"
                reviewers="$reviewers $owners"
              fi
            done < .github/CODEOWNERS
          done
          # Remove duplicates
          reviewers=$(echo "$reviewers" | xargs -n1 | sort -u | xargs)
          if [ -n "$reviewers" ]; then
            # Remove @ from reviewers (it stays in the beginning of the username)
            reviewers_cleaned=${reviewers//@/}
            # Convert reviewers to comma separated list
            reviewers_comma_separated=$(echo "$reviewers_cleaned" | tr ' ' ',')
            echo "Requesting review from: $reviewers_comma_separated"
            gh pr edit ${{ github.event.pull_request.number }} --add-reviewer $reviewers_comma_separated
          else
            echo "No reviewers found for the changed files."
          fi