Function shouldPolyfill

packages/intl-listformat/should-polyfill.ts:15–23

(locale = 'en')

}

export function shouldPolyfill(locale = 'en'): string | undefined {
  if (
    typeof Intl === 'undefined' ||
    !('ListFormat' in Intl) ||
    !supportedLocalesOf(locale)
  ) {
    return locale ? match([locale], supportedLocales, 'en') : undefined
  }
}