A generic Store class, that utilises Immutable.js

Store.js

import { EventEmitter } from "events";
import { Map } from "immutable";

const CHANGE_EVENT = "change";

class Store extends EventEmitter {
  constructor() {
    super();
    this.data = new Map();
  }

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

  set(obj) {
    // Replace the entire data set
    if (obj instanceof Map) {
      this.data = obj;
      this.emitChange();
    }
  }

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

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

    if (this.data !== newData) {
      this.data = newData;
      this.emitChange();
    }
  }

  add(id, element) {
    this.data = this.data.set(id, element);
    this.emitChange();
  }

  emitChange() {
    this.emit(CHANGE_EVENT);
  }

  addChangeListener(callback) {
    this.on(CHANGE_EVENT, callback);
  }

  removeChangeListener(callback) {
    this.removeListener(CHANGE_EVENT, callback);
  }
}

export default Store;