class Sinatra::ShowExceptions

def frame_class(frame)
  if frame.filename =~ %r{lib/sinatra.*\.rb}
    'framework'
  elsif (defined?(Gem) && frame.filename.include?(Gem.dir)) ||
        frame.filename =~ %r{/bin/(\w+)\z}
    'system'
  else
    'app'
  end
end