Где хранить кэшированные данные? (LocalStorage, IndexedDB). Что делать, если IndexedDB не поддерживается?

// Простые данные
localStorage.setItem('user', JSON.stringify(userData));
const user = JSON.parse(localStorage.getItem('user'));

const request = indexedDB.open('MyDatabase', 1);
request.onsuccess = (event) => {
  const db = event.target.result;
  const transaction = db.transaction(['store'], 'readwrite');
  const store = transaction.objectStore('store');
  store.put(data, 'key');
};

const isIndexedDBSupported = () => {
  return 'indexedDB' in window;
};

const isLocalStorageSupported = () => {
  try {
    localStorage.setItem('test', 'test');
    localStorage.removeItem('test');
    return true;
  } catch (e) {
    return false;
  }
};

class StorageAdapter {
  constructor() {
    this.supported = this.detectSupport();
  }

  detectSupport() {
    if (isIndexedDBSupported()) return 'indexeddb';
    if (isLocalStorageSupported()) return 'localstorage';
    return 'none';
  }

  async set(key, value) {
    switch (this.supported) {
      case 'indexeddb':
        return await this.setIndexedDB(key, value);
      case 'localstorage':
        return this.setLocalStorage(key, value);
      default:
        throw new Error('No storage support');
    }
  }

  setLocalStorage(key, value) {
    localStorage.setItem(key, JSON.stringify(value));
  }

  async setIndexedDB(key, value) {
    // Реализация IndexedDB
  }
}