Code snippet of tutorial running tracker

tracker.js

const success = (position) => {
  const { latitude, longitude } = position.coords;
  const timestamp = (new Date(Date.now())).toISOString();

  ...

  createNewEvent(latitude, longitude, timestamp);
}

const createNewEvent = (latitude, longitude, timestamp) => {
  const geoEvent = new CustomEvent("GEO_EVENT", {
    detail: {
      latitude,
      longitude,
      timestamp,
    },
    bubbles: true,
    cancelable: true,
    composed: false,
  });
  
  document.querySelector("#tracker").dispatchEvent(geoEvent);
}

document.querySelector("#tracker")
  .addEventListener("GEO_EVENT", updateMap);