Проверка видимости элемента

В новых браузерах есть свойство HTMLElement.checkVisibility()

export const isVisible = (elem: HTMLElement): boolean => {
  if (!(elem instanceof Element)) throw Error('DomUtil: elem is not an element.');
  const style = getComputedStyle(elem);
  if (style.display === 'none') return false;
  if (style.visibility !== 'visible') return false;
  if (Number(style.opacity) < 0.1) return false;
  if (elem.offsetWidth + elem.offsetHeight + elem.getBoundingClientRect().height +
      elem.getBoundingClientRect().width === 0) {
      return false;
  }
  const elemCenter   = {
      x: elem.getBoundingClientRect().left + elem.offsetWidth / 2,
      y: elem.getBoundingClientRect().top + elem.offsetHeight / 2
  };
  if (elemCenter.x < 0) return false;
  if (elemCenter.x > (document.documentElement.clientWidth || window.innerWidth)) return false;
  if (elemCenter.y < 0) return false;
  if (elemCenter.y > (document.documentElement.clientHeight || window.innerHeight)) return false;
  let pointContainer = document.elementFromPoint(elemCenter.x, elemCenter.y) as HTMLElement;
  do {
      if (pointContainer === elem) return true;
  } while (pointContainer = pointContainer.parentNode as HTMLElement);
  return false;
}