# File lib/rspec/expectations/differ.rb, line 9
      def diff_as_string(data_new, data_old)
        data_old = data_old.split(/\n/).map! { |e| e.chomp }
        data_new = data_new.split(/\n/).map! { |e| e.chomp }
        diffs = Diff::LCS.diff(data_old, data_new)
        output = ""
        return output if diffs.empty?
        oldhunk = hunk = nil
        file_length_difference = 0
        diffs.each do |piece|
          begin
            hunk = Diff::LCS::Hunk.new(
              data_old, data_new, piece, context_lines, file_length_difference
            )
            file_length_difference = hunk.file_length_difference
            next unless oldhunk
            # Hunks may overlap, which is why we need to be careful when our
            # diff includes lines of context. Otherwise, we might print
            # redundant lines.
            if (context_lines > 0) and hunk.overlaps?(oldhunk)
              if hunk.respond_to?(:merge)
                # diff-lcs 1.2.x
                hunk.merge(oldhunk)
              else
                # diff-lcs 1.1.3
                hunk.unshift(oldhunk)
              end
            else
              output << oldhunk.diff(format)
            end
          ensure
            oldhunk = hunk
            output << "\n"
          end
        end
        #Handle the last remaining hunk
        output << oldhunk.diff(format) << "\n"
        color_diff output
      end