isomorphic-localstorage-proxy

storage.js

import { createLocalStorage } from "localstorage-ponyfill";

export const isBrowser =
  typeof window !== 'undefined' &&
  typeof window.document !== 'undefined';

export const isNode =
  typeof process !== 'undefined' &&
  process.versions != null &&
  process.versions.node != null;


const storage = new Proxy (createLocalStorage({
  mode: isNode && 'memory' || (isBrowser && 'browser')
}), {

  get (store, prop) {
    return store.getItem(prop);
  },

  /**
   * Set a keys value
   * @param {storage} store
   * @param {*} prop
   * @param {*} value
   *
   * Return value
   *   The set method should return a boolean value. Return true to indicate that assignment succeeded. If the set method returns false, and the assignment happened in strict-mode code, a TypeError will be thrown.
   */
  set (store, prop, value) {
    store.setItem(prop, value);
    return store.getItem(prop) === value;
  },

  deleteProperty (store, prop) {
    store.removeItem(prop);
  }

});

export default storage;