Sinlge-test-multiple-data unit testing - a test-driver

When writing unit-tests, especially for parsers and similar problems, I tend to write a single-test-multiple-data structure. Out of the box, the support for test driven by an array, or a test-data-factory is bad. So I wrote a test-driver for this exact purpose.

While it does the job, I probably have a lot of issues in the tiny crate.
What are your suggestions for the functionality/code-style?

Thanks a lot in advance. Cheers!