class RuboCop::ResultCache

def file_checksum(file, config_store)
  Digest::MD5.hexdigest(Dir.pwd + file + IO.read(file) +
                        config_store.for(file).to_s)
rescue Errno::ENOENT
  # Spurious files that come and go should not cause a crash, at least not
  # here.
  '_'
end