I hope it's communicated that they're not expected to finish. If I was given a coding challenge with a time limit I would assume I was expected to finish inside

I hope it's communicated that they're not expected to finish. If I was given a coding challenge with a time limit I would assume I was expected to finish inside the time limit and make any sacrifices that needed to be made to achieve that - including ignoring testing and hoping I just don't make too many mistakes.