Importance of having tests in home test assignments when applying for a new job

Question

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)}

Answer 1

A few thoughts:

• What kind of timeframe do candidates have to complete the take home? If it's condensed, tests can seem like a luxury rather than a requirement (though this can give insights into the candidate as well).
• How's the exercise framed? Does it read as a solve this problem, or does it read as develop a full, professional solution?
• In general, instead of lack of tests being a hard no, I flip it the other way and think presence of tests are a bonus.
• I'd rather use the lack of tests to start the discussion on how they approached the problem. They clearly didn't use TDD, but the obvious first question to me would be "how did you verify your solution worked/is correct?"