Being able to run test for a single class is key, but also quite limiting. As scala systems grow, it will be necessary to be able to select a package and run all the ScalaTest tests in the package (or module or entire project).
What's strange is that I'm pretty sure that this was working just a few versions ago. All my scala tests extend JUnit3Suite, and I was able to create a JUnit config for the package and the tests would run. Now when I try that I get the fabled "no tests found" error. So now I limited to running tests one class at a time.