class RuboCop::Cop::Style::ExpandPathArguments

def parent_path(current_path)
  paths = current_path.split(File::SEPARATOR)
  paths.delete('.')
  paths.each_with_index do |path, index|
    if path == '..'
      paths.delete_at(index)
      break
    end
  end
  paths.join(File::SEPARATOR)
end