As any other assignment, the Tiger Project comes with its rules to follow.
It is strictly forbidden to possess code that is not yours. You are encouraged to work with others, but don’t get a copy of their code. See How not to go about a programming assignment, for more hints on what will not be accepted.
Test cases and test engines development are parts of the Tiger Project. As such the same rules apply as for code.
If something illegal happened in the course of a stage, let us know, arrangements might be possible. If we find out, the rules will be strictly applied. It already happened that third year students have had to redo the Tiger Project because their code was found in another group: -42/20 is seldom benign.
Don’t bother everybody instead of trying first. Conversely, once you did your best, don’t hesitate working with others.