React Native Custom Storage for Android

CustomStorage.js

import RNFetchBlob from 'react-native-fetch-blob';

const DocumentDir = RNFetchBlob.fs.dirs.DocumentDir;
const storagePath = `${DocumentDir}/persistStore`;
const encoding = 'utf8';

const toFileName = name => (
  name.split(':').join('-')
);

const fromFileName = name => (
  name.split('-').join(':')
);

const pathForKey = key => (
  `${storagePath}/${toFileName(key)}`
);

const handleError = callback => (error) => {
  if (callback) callback(error);
};

const getItem = async (key, callback) => {
  try {
    const location = pathForKey(toFileName(key));
    const data = await RNFetchBlob.fs.readFile(location, encoding);

    if (callback) callback(null, data);
    return data;
  } catch (error) {
    handleError(callback)(error);
    return null;
  }
};

const setItem = async (key, value, callback) => {
  try {
    await RNFetchBlob.fs.writeFile(pathForKey(key), value, encoding);
    if (callback) callback();
  } catch (error) {
    handleError(callback)(error);
  }
};

const removeItem = async (key, callback) => {
  try {
    const location = pathForKey(toFileName(key));
    await RNFetchBlob.fs.unlink(location);
    if (callback) callback();
  } catch (error) {
    handleError(callback)(error);
  }
};

const getAllKeys = async (callback) => {
  try {
    const isExist = RNFetchBlob.fs.exists(storagePath);
    if (!isExist) return null;

    await RNFetchBlob.fs.mkdir(storagePath);

    const files = await RNFetchBlob.fs.ls(storagePath);
    const results = files.map(file => fromFileName(file));
    if (callback) callback(null, files);
    return results;
  } catch (error) {
    handleError(callback)(error);
    return null;
  }
};

export default {
  setItem,
  getItem,
  removeItem,
  getAllKeys
};

Storage.android.js

import { AsyncStorage } from 'react-native';
import CustomStorage from './CustomStorage';

// AsyncStorage isn't works on the android with debugger attached
// This is a well known issue, even on the latest react-native it still happens
// Many areas depend on AsyncStorage API, which is we are doomed now lol
// Best we can do is on Development Mode, instead use AsyncStorage
// we replace it with our custom storage service instead
// -----------------------------------------------------------
// Further reference: https://github.com/facebook/react-native/issues/12830
const SelectedStorage = __DEV__
  ? CustomStorage
  : AsyncStorage;

export default SelectedStorage;