scratch-www/src/lib/intl-polyfill.js

// this file should only be `required` in the format-time
// when Intl.RelativeTimeFormat is not available (Safari < 14), but
// we're not currently able to do the code splitting in www, and it
// is always included. To reduce the amount of data that's loaded limit
// the number of languages loaded to just the top few that are still using
// safari <14. These seven account for most uses.
// relativetimeformat depends on locale which also needs to be polyfilled in
// safari <14
// The plural rules is required for safari 12.
import {shouldPolyfill as shouldPolyfillLocale} from '@formatjs/intl-locale/should-polyfill';
import {shouldPolyfill as shouldPolyfillRelativeTimeFormat} from '@formatjs/intl-relativetimeformat/should-polyfill';
import {shouldPolyfill as shouldPolyfillPluralRules} from '@formatjs/intl-pluralrules/should-polyfill';
/**
 * polyfill all the parts needed from intl
 * @param  {string} locale currently selected locale
 * @return {Promise}       returns a promise that resolves when everything is loaded
 */
const intlPolyfill = async function (locale) {
    if (!(shouldPolyfillLocale() ||
        shouldPolyfillPluralRules(locale) ||
        shouldPolyfillRelativeTimeFormat(locale))) {
        console.log('NOT polyfilling');
        return;
    }

    if (shouldPolyfillRelativeTimeFormat(locale)) {
        await import('@formatjs/intl-relativetimeformat/polyfill');
    }

    if (shouldPolyfillPluralRules(locale)) {
        await import('@formatjs/intl-pluralrules/polyfill');
    }

    if (shouldPolyfillLocale(locale)) {
        await import('@formatjs/intl-locale/polyfill');
    }

    switch (locale) {
    case 'ar':
        await import('@formatjs/intl-relativetimeformat/locale-data/ar');
        await import('@formatjs/intl-pluralrules/locale-data/ar');
        break;
    case 'es':
    case 'es-419':
        await import('@formatjs/intl-relativetimeformat/locale-data/es');
        await import('@formatjs/intl-pluralrules/locale-data/es');
        break;
    case 'fr':
        await import('@formatjs/intl-relativetimeformat/locale-data/fr');
        await import('@formatjs/intl-pluralrules/locale-data/fr');
        break;
    case 'ja':
        await import('@formatjs/intl-relativetimeformat/locale-data/ja');
        await import('@formatjs/intl-pluralrules/locale-data/ja');
        break;
    case 'tr':
        await import('@formatjs/intl-relativetimeformat/locale-data/tr');
        await import('@formatjs/intl-pluralrules/locale-data/tr');
        break;
    case 'zh':
    case 'zh-CN':
    case 'zh-TW':
        await import('@formatjs/intl-relativetimeformat/locale-data/zh');
        await import('@formatjs/intl-pluralrules/locale-data/zh');
        break;
    default:
        await import('@formatjs/intl-relativetimeformat/locale-data/en');
        await import('@formatjs/intl-pluralrules/locale-data/en');
        break;
    }
};

export default intlPolyfill;