class ActionView::Template::Error

def formatted_code_for(source_code, line_counter, indent, output)
  start_value = (output == :html) ? {} : ""
  source_code.inject(start_value) do |result, line|
    line_counter += 1
    if output == :html
      result.update(line_counter.to_s => "%#{indent}s %s\n" % ["", line])
    else
      result << "%#{indent}s: %s\n" % [line_counter, line]
    end
  end
end