Dispatches event and wait for response event and resolve promise

DuplexListener.js

import SymbolImpl from 'SymbolImpl';
import EventDeferred from 'EventDeferred';

const INTERNALS_FIELD = SymbolImpl('duplex.listener::internals');

class DuplexListener {
  constructor(dispatcher, event, responseEventType, data = null) {
    if (responseEventType) {
      const deferred = new EventDeferred(dispatcher, responseEventType);
      this.promise = deferred.promise;
      this[INTERNALS_FIELD] = deferred;
    } else {
      this.promise = Promise.resolve();
    }
    // INFO This kind of dispatchEvent signature is used 
    // with https://github.com/burdiuz/js-event-dispatcher
    dispatcher.dispatchEvent(event, data);
  }

  get listening() {
    return this[INTERNALS_FIELD] && this[INTERNALS_FIELD].listening || false;
  }

  cancel = () => {
    this[INTERNALS_FIELD] && this[INTERNALS_FIELD].cancel();
  };

  dispose = () => {
    this[INTERNALS_FIELD] && this[INTERNALS_FIELD].dispose();
    delete this[INTERNALS_FIELD];
  };
}

// resolver(eventType:string):string is a function that returns type of response event
export const requestResolverFactory = (resolver) => {
  return (dispatcher) => {
    return (eventType, data = null) => {
      const deferred = new DuplexListener(dispatcher, eventType, resolver(eventType), data);
      return deferred.promise;
    };
  };
};

export default DuplexListener;

package.json

{
  "name": "DuplexListener",
  "description": "Dispatches event and wait for response event and resolve promise",
  "version": "0.0.1",
  "main": "DuplexListener.js",
  "dependencies": {
    "SymbolImpl": "https://gist.github.com/burdiuz/7664491eed84695250e46be20670be84",
    "EventDeferred": "https://gist.github.com/burdiuz/fc54775c907422386fbcad2cf701ab0d"
  }
}