en.javascript.info/2-ui/1-document/05-basic-dom-node-properties/2-tree-info/solution.md

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.