class RuboCop::ResultCache

def rubocop_checksum
  ResultCache.source_checksum ||=
    begin
      lib_root = File.join(File.dirname(__FILE__), '..')
      bin_root = File.join(lib_root, '..', 'bin')
      source = Find.find(lib_root, bin_root).sort.map do |path|
        IO.read(path) if File.file?(path)
      end
      Digest::MD5.hexdigest(source.join)
    end
end