Sample code, redux

render.js

const framesPerSecond = 30;
const frameTimer = 1000 / framesPerSecond;
const now = () => Date.now();

let timer = null;

function render(previousDelta) {
   const start = now();
	 
   move(previousDelta);
   draw();
   
   const end = now();
   const newDelta = end - start;
   
   timer = setTimeout(render, newDelta, frameTimer - newDelta);
}

render(0);