Adding Unit Tests to an already existing project?

Question

When you create an XCode 4 project, it asks you if you want to include unit testing. But how do you add it to a project that\'s been created without them?

I started

Answer 1

Also, if you want to be able to do cmd-U to run your tests then delete the scheme that was created for the test bundle and instead edit your main application scheme and add the test bundle in the Test configuration. See this screenshot: