def describe_file_diff(diff, max_width=80)
      description = []
      description << "File comparison error `#{diff.relative_path}` for #{spec.spec_folder}:"
      description << "--- DIFF ".ljust(max_width, '-')
      description += diff.map do |line|
        case line
          when /^\+/ then line.green
          when /^-/ then  line.red
          else            line
        end.gsub("\n",'').gsub("\r", '\r')
      end
      description << "--- END ".ljust(max_width, '-')
      description << ''
      description * "\n"
    end
def describe_file_diff(diff, max_width=80)
      description = []
      description << "File comparison error `#{diff.relative_path}` for #{spec.spec_folder}:"
      description << "--- DIFF ".ljust(max_width, '-')
      description += diff.map do |line|
        case line
          when /^\+/ then line.green
          when /^-/ then  line.red
          else            line
        end.gsub("\n",'').gsub("\r", '\r')
      end
      description << "--- END ".ljust(max_width, '-')
      description << ''
      description * "\n"
    end
Return a description text for an expectation that two files were
 expected to be the same, but are not.

 @param  [Diff] diff
         the diff which holds the difference

 @param  [Integer] max_width
         the max width of the terminal to print matching separators

 @return [String]