class ActionDispatch::ExceptionWrapper

def source_fragment(path, line)
  return unless Rails.respond_to?(:root) && Rails.root
  full_path = Rails.root.join(path)
  if File.exist?(full_path)
    File.open(full_path, "r") do |file|
      start = [line - 3, 0].max
      lines = file.each_line.drop(start).take(6)
      Hash[*(start+1..(lines.count+start)).zip(lines).flatten]
    end
  end
end