JSFiddle - React, Tailwind, and code Playground

Babel + JSX

let t = 0
setInterval(async function() {
  t = t + 1
  console.log("timer: ", t)
}, 1000)

async function syncDelay(ms) {
  console.log("syncDelay: ", ms, "ms")
  let t1 = Date.now()
  while (Date.now() - t1 < ms) {}
  return ms
}

async function heavyWork() {
  for (let i = 0; i < 10; i++) {
    await syncDelay(500)
  }
}

heavyWork()
console.log("after calling heavyWork")