prettier.yml

name: Auto-format with Prettier
on:
  pull_request:

permissions:
  contents: write

jobs:
  prettier:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0  # important so git diff works

      - uses: actions/setup-node@v4

      - name: Install deps
        run: yarn

      - name: Run prettier on changed files
        run: |
          CHANGED_FILES=$(git diff --name-only origin/${{ github.base_ref }}...HEAD \
            | grep -E '\.(ts|tsx|js|jsx|json|md|yaml|yml|css|scss)$' || true)

          if [ -n "$CHANGED_FILES" ]; then
            FILES_TO_FORMAT=""

            while IFS= read -r file; do
              if [ -f "$file" ]; then
                FILES_TO_FORMAT="$FILES_TO_FORMAT\n$file"
              else
                echo "Skipping missing file: $file"
              fi
            done <<< "$CHANGED_FILES"

            if [ -n "$FILES_TO_FORMAT" ]; then
              printf "%b\n" "$FILES_TO_FORMAT" | sed '/^$/d' | xargs yarn prettier --write
            else
              echo "No existing files to format"
            fi
          else
            echo "No files to format"
          fi

      - name: Commit formatted changes
        run: |
          git config user.name "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"

          if [ -n "$(git status --porcelain)" ]; then
            # Check out the PR branch to avoid detached HEAD
            git checkout ${{ github.head_ref }}
            git add --all
            git commit -m "chore: Apply Prettier formatting"
            git push origin ${{ github.head_ref }}
          else
            echo "No formatting changes to commit"
          fi