Function shouldPolyfill

packages/intl-datetimeformat/should-polyfill.ts:58–71

(locale = 'en')

}

export function shouldPolyfill(locale = 'en'): string | undefined {
  if (
    typeof Intl === 'undefined' ||
    !('DateTimeFormat' in Intl) ||
    !('formatToParts' in Intl.DateTimeFormat.prototype) ||
    !('formatRange' in Intl.DateTimeFormat.prototype) ||
    hasChromeLt71Bug() ||
    hasUnthrownDateTimeStyleBug() ||
    !supportsDateStyle() ||
    !supportedLocalesOf(locale)
  ) {
    return locale ? match([locale], supportedLocales, 'en') : undefined
  }
}