ThinkRX: next'ing a ReplaySubject within a subscription to that ReplaySubject emits value immediately

replaysubject-quirk.js

const { rxObserver } = require('api/v0.3');
const { ReplaySubject } = require('rxjs');

const myReplaySubj = new ReplaySubject();

myReplaySubj.next(1);
myReplaySubj.next(2);
myReplaySubj.next(3);

let didEmitNewValues = false;

const thinkRx = rxObserver();
myReplaySubj.subscribe((val) => {
  thinkRx.next(val); // Draw value in diagram
  if(!didEmitNewValues) {
    didEmitNewValues = true;
    myReplaySubj.next(4);
    myReplaySubj.next(5);
  }
});

Link to ThinkRX: https://thinkrx.io/gist/55cdad6589f662c6a0a7b8228523968a/