Function transform_test_with_dir 

pub fn transform_test_with_dir<TS>(input: TS) -> TS
where
    TokenStream: From<TS>,
    TS: From<TokenStream>,

Transform a token stream of a test function definition into a proper #[test] fn

This requires the input to be a fn item just like a standard #[test] function except it takes a single std::path::PathBuf argument to an empty test-specific directory. Any return type is propagated, although any errors during setting up the test directory cause panics.

Almost every use of this function would be via the test_with_dir macro within the target-test-dir crate; see that crate for examples.