url= in html turns up undefined when clicking link

https://www.khanacademy.org/computer-programming/url-href/5014921009168384
When using test, the live editor isn't detecting the link. It just prints out "undefined" instead of saying "link". Could be used by other users to link to a dangerous site without the user knowing what site they are visiting

Reproduce the issue using the linked Khan Academy live-editor example and the provided test snippet. Trace how the editor handles anchor attributes, then verify that the link destination is detected instead of producing "undefined" and that the resulting behavior matches the issue's safety concern.

Written by the indexing model from the issue text.