A generic Store factory, that utilises Immutable.js and RxJS

Store.js

import { EventEmitter } from "events";
import { Observable } from "rx";
import { Map, List } from "immutable";

export default {
  createStore(extend) {
    const CHANGE_EVENT = "change";
    const EventListener = Object.assign({}, EventEmitter.prototype, {
      changed() {
        this.emit(CHANGE_EVENT);
      }
    });

    return Object.assign({
      data: new Map(),

      stream: Observable.fromEvent(EventListener, CHANGE_EVENT)
        .publish()
        .refCount(),

      get(id) {
        if (id) {
          return this.data.get(id);
        } else {
          return this.data.toList();
        }
      },

      set(key, value) {
        this.data = this.data.set(key, value);
        EventListener.changed();
      },

      empty() {
        this.data = new Map();
      },

      count() {
        return this.data.size;
      },

      remove(id) {
        const _data = this.data.delete(id);

        if (_data.size !== this.data) {
          this.data = _data;
          EventListener.changed();
        }
      }
    }, extend);
  }
};