clang-format-check.yml

name: Clang Format Check

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

jobs:
  clang-format-check:
    name: Check PR formatting with clang-format-15
    runs-on: ubuntu-latest

    steps:
    - name: Checkout code
      uses: actions/checkout@v4
      with:
        fetch-depth: 0  # Need full history to compare with main branch

    - name: Install clang-format-15
      run: |
        sudo apt-get install -y clang-format-15

    - name: Fetch base branch
      env:
        BASE_REF: ${{ github.event.pull_request.base.ref }}
      run: |
        git fetch origin "$BASE_REF:$BASE_REF"

    - name: Check formatting
      env:
        BASE_SHA: ${{ github.event.pull_request.base.sha }}
        BASE_REF: ${{ github.event.pull_request.base.ref }}
      run: |
        echo "Running git-clang-format-15 to check for formatting issues..."
        echo "Comparing against base branch: $BASE_REF"

        # Create a temporary file for the diff and ensure cleanup
        DIFF_FILE="$(mktemp)"
        trap 'rm -f "$DIFF_FILE"' EXIT

        # Run git-clang-format against the PR base commit and capture status safely under set -e
        if git-clang-format-15 "$BASE_REF" > "$DIFF_FILE"; then
          status=0
        else
          status=$?
        fi
        if [ "$status" -eq 0 ]; then
          echo "✅ Code is properly formatted!"
          exit 0
        elif [ "$status" -eq 1 ]; then
          echo "❌ Code formatting issues detected!"
          echo ""
          echo "The following changes would be made by clang-format-15:"
          echo "=================================================="
          cat "$DIFF_FILE"
          echo "=================================================="
          echo ""
          echo "Please run the following command locally on your feature branch and commit the changes:"
          echo "  git-clang-format-15 $BASE_REF"
          exit 1
        else
          echo "❌ git-clang-format-15 failed with exit code $status"
          echo "Output (if any):"
          cat "$DIFF_FILE"
          exit 1
        fi