How to poll a promise in repeating syncroneous code?

Let's say we have some Promise for we knew it resolves at some point. Now I have sync code (ag. no await possible) called repeatedly (eg. onAnimationFrame). How to use the result of the promise there, if it is fullfilled?

Like (JS pseudocode):

let promise=FetchSomething();
let updater = ()=>{
  drawSomething();
  if(promise IS FULLFILLED)  // how to know if fullfilled?
    drawThing(RESULT OF promise); // how to get the result here?
  requestAnimationFrame(updater);
}
updater();

The easiest way is to set a variable yourself:

let promise = FetchSomething();
let done = false

/* variable will be set once promise settled */
promise.then(() => {
    done = true
})

let updater = () => {
  drawSomething();

  if (done) {  
      drawThing(/* RESULT OF promise */); 
  }

  requestAnimationFrame(updater);
}

updater();

You can do the same with the result, i.e.:

let promise = FetchSomething();
let done = false
let result = null

promise.then((value) => {
    done = true
    result = value
})

let updater = () => {
  drawSomething();

  if (done) {  
      drawThing(result); 
  }

  requestAnimationFrame(updater);
}

updater();