The test method needs to be checked, we are checking this only with class name. Might be good idea to extend this to do method visitor. 

Having test methods from same class scattered over multiple files is indeed a problem. My suggestion to this, would be to limit the search to methods. Import the first file that contains the first test method. And flag violations in the file to any test method that is not included in the same file. I think is a good practice todo so.