AmplifyAuthAsyncStorageConfig.js

/** taken from https://aws-amplify.github.io/docs/js/authentication */
import { AsyncStorage } from '@react-native-community/async-storage';
import { Auth } from '@aws-amplify/auth';

const MEMORY_KEY_PREFIX = '@MyStorage:';
let dataMemory = {};

/** @class */
class MyStorage {
  static syncPromise = null;

  /**
     * This is used to set a specific item in storage
     */
  static setItem(key, value) {
    AsyncStorage.setItem(MEMORY_KEY_PREFIX + key, value);
    dataMemory[key] = value;
    return dataMemory[key];
  }

  /**
     * This is used to get a specific key from storage
     */
  static getItem(key) {
    return Object.prototype.hasOwnProperty.call(dataMemory, key) ? dataMemory[key] : undefined;
  }

  /**
     * This is used to remove an item from storage
     */
  static removeItem(key) {
    AsyncStorage.removeItem(MEMORY_KEY_PREFIX + key);
    return delete dataMemory[key];
  }

  /**
     * This is used to clear the storage
     */
  static clear() {
    dataMemory = {};
    return dataMemory;
  }

  /**
     * Will sync the MemoryStorage data from AsyncStorage to storageWindow MemoryStorage
    */
  static sync() {
    if (!MyStorage.syncPromise) {
      MyStorage.syncPromise = new Promise((res, rej) => {
        AsyncStorage.getAllKeys((errKeys, keys) => {
          if (errKeys) rej(errKeys);
          const memoryKeys = keys.filter(key => key.startsWith(MEMORY_KEY_PREFIX));
          AsyncStorage.multiGet(memoryKeys, (err, stores) => {
            if (err) rej(err);
            stores.map((result, index, store) => {
              const key = store[index][0];
              const value = store[index][1];
              const memoryKey = key.replace(MEMORY_KEY_PREFIX, '');
              dataMemory[memoryKey] = value;
            });
            res();
          });
        });
      });
    }
    return MyStorage.syncPromise;
  }
}

Auth.configure({
  storage: MyStorage,
});