Yield to main thread

yield-to-main.js

/*
* Yielding method using scheduler.yield, falling back to setTimeout:
*/
async function yieldToMain() {
  if('scheduler' in window && 'yield' in scheduler) {
    return await scheduler.yield();
  }

  return new Promise(resolve => {
    setTimeout(resolve, 0);
  });
}

/*
* Yielding to the main thread before changing the state of the component:
*/
const observer = new IntersectionObserver((entries) => {
  entries.forEach(handleIntersection);
  const maxNumberOfEntries = Math.max(...this.intersectingEntries);

  if (Number.isFinite(maxNumberOfEntries)) {
    await this.yieldToMain();

    this.setState({ count: maxNumberOfEntries });
  }
}, { threshold: 0.5 });