@formatjs/intl-enumerator/src/get-supported-calendars.js

Intl.Enumerator polyfill

import { createMemoizedDateTimeFormat } from "@formatjs/ecma402-abstract";
import { calendars } from "./calendars.generated.js";
function isSupportedCalendar(item, locale = "en") {
	try {
		const dateTimeFormat = createMemoizedDateTimeFormat(`${locale}-u-ca-${item}`);
		const options = dateTimeFormat.resolvedOptions().calendar;
		if (item !== "gregory" || options !== "gregory") return true;
	} catch {}
	return false;
}
export function getSupportedCalendars(localePrefix) {
	return calendars.filter((calendar) => isSupportedCalendar(calendar, localePrefix));
}