class RuboCop::ResultCache

def file_checksum(file, config_store)
  digester = Digest::MD5.new
  mode = File.stat(file).mode
  digester.update(
    "#{@pwd}#{file}#{mode}#{config_store.for(file).signature}"
  )
  digester.file(file)
  digester.hexdigest
rescue Errno::ENOENT
  # Spurious files that come and go should not cause a crash, at least not
  # here.
  '_'
end