class Sprockets::Base

def file_digest(path)
  if stat = self.stat(path)
    # If its a file, digest the contents
    if stat.file?
      digest.file(path.to_s)
    # If its a directive, digest the list of filenames
    elsif stat.directory?
      contents = self.entries(path).join(',')
      digest.update(contents)
    end
  end
end