Nested Ternaries

Instead of something like the following

if (val > root.val) {
  return contains(root.right, val)
} else if (val < root.val) {
  return contains(root.left, val)
} else {
  return true
}

This is a shortened version. Make sure to follow this format to make it more easily readable

(val > root.val)
  ? contains(root.right, val)
  : (val < root.val)
    ? contains(root.left, val)
    : true