Is there a folder layout convention for test sources files and test resources files?

In https://gradle.github.io/playframework/#project_layout, it describes a /test folder to hold test files. But didn't mention about test sources files and test resources files.
Is there a convention for test resources files?
I see some play apps are having /test/ folder to contain test sources files and /test/resources to contain test resources files, I am wondering if this is a good approach and if it is following gradle play best practice convention.

In my understanding a normal approach is to have different dedicated folder for test sources files and test resources files, e.g. /test/java for test sources files and /test/resources/ for test resources files.