storageDriver for Cycle.js

storage-driver.js

import { ReplaySubject } from 'rxjs';

function StorageWrapper(storage) {
  function set(key, value) {
    storage.setItem(key, JSON.stringify(value));
    return value;
  }

  function get(key) {
    return JSON.parse(storage.getItem(key))
  }

  function getAll() {
    return Object.keys(storage).map(key => {
      const item = {};
      item[key] = get(key);
      return item; 
    });
  }

  function remove(key) {
    const item = get(key);
    storage.removeItem(key);
    return item[key];
  }

  function clear() {
    return storage.clear();
  }

  const wrappedStorage = { set, get, getAll, remove, clear };

  Object.defineProperty(wrappedStorage, 'length', { get: () => storage.length });

  return wrappedStorage;
}

export function makeStorageDriver(storageType) {
  let type;

  if (typeof storageType === 'string') {
    type = storageType.toLowerCase();
  } else {
    console.error('Invalid argument. "makeStorageDriver" accepts a string as argument.');
  }

  if (!['local', 'session'].includes(type)) {
    console.error('Invalid argument. The argument for "makeStorageDriver" must be "local" or "session".');
  }

  const storage = StorageWrapper(window[`${type}Storage`]);

  const storageSource$ = new ReplaySubject();
  storageSource$.next(storage);

  function storageDriver(storage$) {
    storage$.switchMapTo(storageSource$).subscribe(storageSource$);
    return storageSource$;
  };

  return storageDriver;
}