import extension from 'extensionizer' import promisify from 'pify' import allLocales from '../../_locales/index.json' const getPreferredLocales = extension.i18n ? promisify( extension.i18n.getAcceptLanguages, { errorFirst: false }, ) : async () => [] // mapping some browsers return hyphen instead underscore in locale codes (e.g. zh_TW -> zh-tw) const existingLocaleCodes = {} allLocales.forEach((locale) => { if (locale && locale.code) { existingLocaleCodes[locale.code.toLowerCase().replace('_', '-')] = locale.code } }) /** * Returns a preferred language code, based on settings within the user's browser. If we have no translations for the * users preferred locales, 'en' is returned. * * @returns {Promise} - Promises a locale code, either one from the user's preferred list that we have a translation for, or 'en' * */ export default async function getFirstPreferredLangCode () { let userPreferredLocaleCodes try { userPreferredLocaleCodes = await getPreferredLocales() } catch (e) { // Brave currently throws when calling getAcceptLanguages, so this handles that. userPreferredLocaleCodes = [] } // safeguard for Brave Browser until they implement chrome.i18n.getAcceptLanguages // https://github.com/MetaMask/metamask-extension/issues/4270 if (!userPreferredLocaleCodes) { userPreferredLocaleCodes = [] } const firstPreferredLangCode = userPreferredLocaleCodes .map((code) => code.toLowerCase().replace('_', '-')) .find((code) => Object.prototype.hasOwnProperty.call(existingLocaleCodes, code)) return existingLocaleCodes[firstPreferredLangCode] || 'en' }