Count descendants

There’s a tree structured as nested ul/li.

Write the code that for each <li> shows:

What’s the text inside it (without the subtree)
The number of nested <li> – all descendants, including the deeply nested ones.

Let’s make a loop over <li>:

          for (let li of document.querySelectorAll('li')) {
  ...
}
        

In the loop we need to get the text inside every li.

We can read the text from the first child node of li, that is the text node:

          for (let li of document.querySelectorAll('li')) {
  let title = li.firstChild.data;

  // title is the text in <li> before any other nodes
}
        

Then we can get the number of descendants as li.getElementsByTagName('li').length.

Open the solution in a sandbox.