Exactly. This isn't a major, it's a class at most. I'm a Mechanical engineer and took a few CS classes as electives.I was the only one in my class of CS majors that would unit test. I wrote script upon script to beat my projects to death. Consequently I also managed to get one of the highest grades in the class. This was back in 2003 when "CS" meant "I like computers" but there were numerous people in my class that would turn in half assed work.
Even at work where I use Matlab I try to test every single scenario possible in my scripts. Especially the stuff that I put on Matlab File Exchange, for example: https://github.com/jedediahfrey/matlab_saveppt2/blob/master/Test_SavePPT2.m