pr-format-check.yml

name: PR Format Check

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

jobs:
  clang-format:
    name: Clang Format
    runs-on: ubuntu-latest
    permissions:
      contents: read
      pull-requests: write

    steps:
    - name: Checkout PR
      uses: actions/checkout@v4
      with:
        fetch-depth: 0
        submodules: recursive

    - name: Install clang-format
      run: |
        sudo apt-get update
        sudo apt-get install -y clang-format-14

    - name: Check changed files
      id: changed-files
      run: |
        # Get list of changed C/C++ files (excluding submodules)
        git diff --name-only origin/${{ github.base_ref }}...HEAD | \
          grep -E '\.(h|hpp|c|cc|cpp)$' | \
          grep -v '^third_party/' > changed_files.txt || true

        if [ -s changed_files.txt ]; then
          echo "has_changes=true" >> $GITHUB_OUTPUT
          echo "Changed C/C++ files:"
          cat changed_files.txt
        else
          echo "has_changes=false" >> $GITHUB_OUTPUT
          echo "No C/C++ files changed"
        fi

    - name: Check formatting of changed files
      if: steps.changed-files.outputs.has_changes == 'true'
      run: |
        exit_code=0
        while IFS= read -r file; do
          if [ -f "$file" ]; then
            echo "Checking $file..."
            clang-format-14 --style=file --dry-run --Werror "$file" || {
              echo "::error file=$file::File is not properly formatted"
              exit_code=1
            }
          fi
        done < changed_files.txt

        if [ $exit_code -ne 0 ]; then
          echo ""
          echo "::error::Some files are not properly formatted."
          echo "To fix, run: make format"
          exit 1
        fi

    - name: Post PR comment on failure
      if: failure() && steps.changed-files.outputs.has_changes == 'true'
      uses: actions/github-script@v7
      with:
        script: |
          const comment = `## Code Formatting Check Failed

          Some files in this PR are not properly formatted according to the project's clang-format rules.

          **To fix this issue:**
          \`\`\`bash
          make format
          \`\`\`

          Then commit and push the changes.`;

          github.rest.issues.createComment({
            issue_number: context.issue.number,
            owner: context.repo.owner,
            repo: context.repo.repo,
            body: comment
          });