If You use to_string, You will see the real nature of module’s name.
This is one of mine…
to_string Pr3f.Application
"Elixir.Pr3f.Application"
There is no correspondance with the name You give and related file system. It is very flexible and You could give any name, in any directory, that would be just fine. Convention is to do what You prefer 
But for test, convention is to not use Test as a directory, but as MyApp/MyFileTest. And don’t forget they are just scripts… as they have exs extension. They are not compiled.
