Anybody remember "cram"? From about 10 years ago, https://bitheap.org/cram/ basically a markdown syntax (making heavy use of code-blocks) for documenting and writing tests as "shell commands and expected output" (with a bunch of the sharp edges filed off, like line endings and partial matches.) Was particularly good for easy-to-write, easy-to-review tests of unix utilities. (It's the kind of thing that you only stumble on if you've been working with doctests but they don't really fit well for shell/unix stuff...)

Speaking of test suites, LLMs cannot quite curl straight quotes correctly. My Markdown editor uses the following suite:

https://repo.autonoma.ca/repo/keenquotes/tree/HEAD/src/test/...

Am curious whether SOTA LLMs can curl the ambiguous cases.

You can also write Gherkin in markdown and have test fixtures for each given, when, then

The "test anything protocol" was a text based system for writing tests, I think perl might still use it

I remember using it to implement the test suite for a Shakespeare language interpreter. Fun times.

https://en.wikipedia.org/wiki/Test_Anything_Protocol

Interesting approach, I can see the benefits of such approach where the md is acting like a Jupyter notebook of some sort. You place the content with documentation and it becomes a self standing unit of test.

I wonder if this can be replicated to other notions where the docs/data needed for test add more value to live with the test

I think you will like https://voiden.md/ - some what similar to what you did here.

PS: I am currently working on Voiden.