AWS Amplify Custom Asyncstorage

authStorage.ts

import {Auth} from 'aws-amplify';
import AsyncStorage from '@react-native-community/async-storage';
import {ICognitoStorage} from 'amazon-cognito-identity-js';

const MEMORY_KEY_PREFIX = '@fcAuth:';
let dataMemory = {};
const syncPromise: Promise<any> = null;

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

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

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

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

/**
 * Will sync the MemoryStorage data from AsyncStorage to storageWindow MemoryStorage
 */
async function sync() {
  if (!syncPromise) {
    try {
      // syncPromise = new Promise((res, rej) => {
      const keys = await AsyncStorage.getAllKeys();

      const memoryKeys = keys.filter((key: string) =>
        key.startsWith(MEMORY_KEY_PREFIX),
      );

      const stores: string[][] = await AsyncStorage.multiGet(memoryKeys);

      stores.map((store: string[]) => {
        const key = store[0];
        const value = store[1];
        const memoryKey = key.replace(MEMORY_KEY_PREFIX, '');

        dataMemory[memoryKey] = value;
      });
    } catch (err) {
      console.error(err);
    }
  }

  return syncPromise;
}

export const AuthStorage: ICognitoStorage & {sync: () => Promise<any>} = {
  setItem,
  getItem,
  removeItem,
  clear,
  sync,
};

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