JSFiddle - React, Tailwind, and code Playground

HTML

<div id="log">

JavaScript

var timeStart = new Date().getTime();

function log(text) {
	var timeNow = new Date().getTime();
	var duration = timeNow - timeStart;
	$("#log").html($("#log").html() + duration + 'ms - ' + text + "<br />")
}


function fakeFeed(out, timeout) {
  return new Promise((resolve, reject) => {
    setTimeout(() => { log(out); resolve(out); }, timeout);
  })
}

async function main2() {
  const ff1 = fakeFeed('feed 1', 4000);
  const ff2 = fakeFeed('feed 2', 200);
  await ff1;
  await ff2;
}
main2().then(
  fulfilled => log('feeds fulfilled'),
  rejected => log('error')
);