title: How to check to see if a scrollbar is present in React?
body: <p>I haven't seen a thread that handles this, at least not for React. </p>
  
  <p>My case: I want to conditionally render a back to top button only when scrolling is an option. It makes no sense to have such a feature if it can't affect the page. </p>
  
  <p>The only solutions I can find are in jQuery. I'm using react-scroll but couldn't find any functionality there for this. </p>