localStorage with fallbacks and serialization

storage.js

/**
 * Setup custom localStorage instance. 
 * If we can't find localStorage, use a Map to use as a 'sessionStorage' clone.
 * @returns {Storage}
 */
function setup () {
  var storage = localStorage
    ? localStorage
    : window.localStorage
      ? window.localStorage
      : global.localStorage
        ? global.localStorage
        : new Map();
  if (!storage.prototype.get) {
    storage.prototype.get = function (_key) {
      let value = storage.getItem(_key) || storage[_key] || null
      return JSON.parse(value) || null;
    }
  }
  if (!storage.prototype.set) {
    storage.prototype.set = function (_key, _value) {
      let value = JSON.stringify(_value, null, 0)
      storage.setItem(_key, value) || (storage[_key] = value)
      return storage
    }
  }
  if (!storage.prototype.remove) {
    storage.protoype.remove = function (_key) {
      storage.removeItem(_key) || storage.delete(_key);
      return storage;
    }
  }
  return storage;
}

/**
 * Get a value from our Storage object, creating it first if necessary.
 * @param {*} key the unique key whose value we want to fetch
 * @param {*} fallback value to return in case of failure retrieving from localStorage
 * @returns {unknown}
 */
function get (key = '', fallback = '') {
  if (!storage) var storage = setup();
  return storage.get(key) || fallback;
}

/**
 * Set a value in our Storage object, creating it first if necessary.
 * @param {string} key the unique key whose value we want to fetch
 * @param {*} value the value to serialize and store
 * @returns {unknown}
 */
function set (key = '', value) {
  if (!storage) var storage = setup();
  return storage.set(key, value)
}

/**
 * Remove an entry from the storage object
 * @param {*} key 
 * @returns 
 */
function remove (key = '') {
  if (!storage) var storage = setup();
  return storage.remove(key)
}