Implement wildcard querySelector to extract URL

Problem: Extract a hidden URL from a deeply nested DOM

A webpage hides a URL by splitting it into individual characters stored in DOM elements. The DOM structure is deeply nested, and you are not allowed to use the browser’s built-in querySelector/querySelectorAll.

You must implement a simplified selector engine and use it to locate the hidden characters.

DOM snippet (example)

<section data-id="23*">
  <article data-class="*45">
    <div data-tag="*78*">
      <b class="ref" value="h"></b>
      <b class="ref" value="t"></b>
      <b class="ref" value="t"></b>
      <b class="ref" value="p"></b>
      <!-- ...more <b> nodes each holding one character... -->
    </div>
  </article>
</section>

Selector syntax you must support

Implement:

function querySelectorAll(root, selector) { /* ... */ }

Where selector is a descendant chain separated by spaces, e.g.

section[data-id="23*"] article[data-class="*45"] div[data-tag="*78*"] b.ref

Each segment may contain:

• a tag name (e.g., section , div , b )
• at most one class (e.g., .ref )
• at most one attribute filter like [data-id="PATTERN"]

Attribute filter patterns may include * wildcards:

• * matches any string (including empty)
• Examples:
  • "23*" matches "23" , "230" , "23abc"
  • "*45" matches "45" , "abc45"
  • "*78*" matches "78" , "a78b" , "xx78"

Task

1. Implement querySelectorAll(root, selector) to return all matching elements in document order .
2. Use it to find all matching <b class="ref"> nodes and reconstruct the URL by concatenating each node’s value attribute in order.

Output

Return the reconstructed URL as a string.

Constraints / assumptions

• The DOM is a tree of elements with tagName , getAttribute(name) , classList , and children (or equivalent).
• No commas, > , + , :nth-child , or other CSS features—only the subset described above.
• The hidden URL characters appear in the correct order in the DOM traversal order under the matched container.