How do you test that child actually contains the next Element Sibling or if there was NO next sibling found?
child = await page.evaluateHandle(el => el.nextElementSibling, child);
Nothing I've found seems to work. :(
Finally figured it out.
.nextElementSibling - returns a Node object or null.
.evaluateHandle - returns a jsHandle containing that result.
So you have to process the jsHandle container which holds the result.
jsHandle.asElement() - Returns either null or the object handle itself, if the object handle is an instance of ElementHandle.
You test for a failed result with:
if (child.asElement() === null) {
//do something
}