formatTranslationMessages = (locale, messages) => {
  const defaultFormattedMessages = locale !== DEFAULT_LOCALE
    ? formatTranslationMessages(DEFAULT_LOCALE, enTranslationMessages)
    : {}
  const formattedMessages = {}
  const messageKeys = Object.keys(messages)
  for (const messageKey of messageKeys) {
    if (locale === DEFAULT_LOCALE) {
      formattedMessages[messageKey] = messages[messageKey]
    } else {
      formattedMessages[messageKey] = messages[messageKey] || defaultFormattedMessages[messageKey]
    }
  }

  return formattedMessages
}
This will setup the i18n language files and locale data for your app.