I've been a part of the interviewing process for Software Engineering positions (including QA engineers as well) in our team for the past several years and I am still struggling to determine my position regarding expecting tests for home-test assignments. For some people in our team absence of tests is an automatic and hard No.
But, I usually try to ask why are there no unit-tests and had received a variety of different answers mostly around: "I did not know they were needed", "I did not have time" or a more honest "I did not know how to test this particular code but would like to discuss it".
And, I think, I've learned to look a bit deeper and try to use this situation to get signals of whether a person is focused on quality and how important testing and checking candidate's own work is for a candidate.
Is this a good approach? What could it potentially mean when there is a home-test assignment submission but with no tests? When is it not a bad sign?
(I understand that the question is generic, please let me know and I can add more details)