React loadable visibility -https://github.com/stratiformltd/react-loadable-visibility/blob/master/src/createLoadableVisibilityComponent.js

createLoadableVisibilityComponent.js

let intersectionObserver;
const trackedElements = new Map();

if (IntersectionObserver) {
  intersectionObserver = new window.IntersectionObserver(
    (entries, observer) => {
      entries.forEach(entry => {
        const visibilityHandler = trackedElements.get(entry.target);

        if (
          visibilityHandler &&
          (entry.isIntersecting || entry.intersectionRatio > 0)
        ) {
          visibilityHandler();
        }
      });
    }
  );
}