Do you put unit tests in same project or another project?

Question

Do you put unit tests in the same project for convenience or do you put them in a separate assembly?

If you put them in a separate assembly like we do, we end up wit

Answer 1

My unit tests always go in a separate project. In fact, for every project I have in my solution, there is a separate test project that goes along with it. Testing code is not application code and should not be intermingled with it. One advantage to keeping them in separate projects -- at least using TestDriven.Net -- is that I can right-click on a test project and run all the tests in that project, testing an entire library of application code with one click.