DOM Tree Walk 2: Find Closest Ancestor

Challenge summary

Collect text from a DOM-like subtree while supporting nested elements and sparse node shapes.

What you'll practice

• Accumulate text without inserting unrequested separators.
• Traverse nested child collections in document order.
• Ignore unsupported nodes without losing valid descendant text.

What Premium unlocks

Premium unlocks the runnable workspace, behavioral checks, implementation walkthrough, and edge-case discussion.