utils.js

export function warn(...args) {
  if (console && console.warn) {
    if (typeof args[0] === 'string') args[0] = `react-i18next:: ${args[0]}`;
    console.warn.apply(console, args);
  }
}

const alreadyWarned = {};
export function warnOnce(...args) {
  if (typeof args[0] === 'string' && alreadyWarned[args[0]]) return;
  if (typeof args[0] === 'string') alreadyWarned[args[0]] = new Date();
  warn(...args);
}

// not needed right now
//
// export function deprecated(...args) {
//   if (process && process.env && (!process.env.NODE_ENV || process.env.NODE_ENV === 'development')) {
//     if (typeof args[0] === 'string') args[0] = `deprecation warning -> ${args[0]}`;
//     warnOnce(...args);
//   }
// }

export function loadNamespaces(i18n, ns, cb) {
  i18n.loadNamespaces(ns, () => {
    // delay ready if not yet initialized i18n instance
    if (i18n.isInitialized) {
      cb();
    } else {
      const initialized = () => {
        // due to emitter removing issue in i18next we need to delay remove
        setImmediate(() => {
          i18n.off('initialized', initialized);
        });
        cb();
      };

      i18n.on('initialized', initialized);
    }
  });
}

export function hasLoadedNamespace(ns, i18n) {
  if (!i18n.languages || !i18n.languages.length) {
    warnOnce('i18n.languages were undefined or empty', i18n.languages);
    return true;
  }

  const lng = i18n.languages[0];
  const fallbackLng = i18n.options ? i18n.options.fallbackLng : false;
  const lastLng = i18n.languages[i18n.languages.length - 1];

  // we're in cimode so this shall pass
  if (lng.toLowerCase() === 'cimode') return true;

  const loadNotPending = (l, n) => {
    const loadState = i18n.services.backendConnector.state[`${l}|${n}`];
    return loadState === -1 || loadState === 2;
  };

  // loaded -> SUCCESS
  if (i18n.hasResourceBundle(lng, ns)) return true;

  // were not loading at all -> SEMI SUCCESS
  if (!i18n.services.backendConnector.backend) return true;

  // failed loading ns - but at least fallback is not pending -> SEMI SUCCESS
  if (loadNotPending(lng, ns) && (!fallbackLng || loadNotPending(lastLng, ns))) return true;

  return false;
}