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

I would say keep them separate.

On top of the other reasons mentioned, having code and tests together skews test coverage numbers. When you report on unit test coverage - reported coverage is higher because the tests are covered when you run unit tests. When you report on integration test coverage, the reported coverage is lower because integration tests would not run unit tests.