Add a trait, WithTestingDirectory, that will automatically create a test directory structure based on Scalatest information. This provides a type class implementation of HasTestingDirectory, but with better Scalatest-specific directories as opposed to generic timestamp-based ones.

This necessarily introduces a provided ("compile only" to Mill) dependency on Scalatest for Chisel. This prevents making all of Chisel pull in Scalatest and relies on the user to load it.

E.g., the included test will create the following directory structure:

build
└── WithTestingDirectorySpec
    └── A-test-suite-mixing-in-WithTestingDirectory
        ├── should-generate-a-directory-structure-derived-from-the-suite-and-test-name
        ├── should-generate-another-directory,-too
        ├── should-handle-CJK-characters,-e.g.,-好猫咪
        └── should-handle-emojis,-e.g.,-🚀

Release Notes

Add WithTestingDirectory Scalatest suite mix-in that automatically sets up a Scalatest-specific directory structure for your tests.