That depends entirely on the context of your CS1 course. Are you teaching unit testing suite to your students? If you haven't learned something then how can you use it? If unittest is part of the curriculum, then definitely students should use it. At my University, students are formally introduced to the JUnit suite during 2nd year, and thus for all their Java projects they are required to have their own testing suite. As for their C projects, we do not require unittesting because gdb is already enough hair pulling.

That depends entirely on the context of your CS1 course. Are you teaching unit testing suite to your students? If you haven't learned something then how can you use it? If unittest is part of the curriculum, then definitely students should use it. At my University, students are formally introduced to the JUnit suite during 2nd year, and thus for all their Java projects they are required to have their own testing suite. As for their C projects, we do not require unittesting because gdb is already enough hair pulling.

So to answer your question, no we are not using unit testing in CS1 because it has not been formally taught yet.