Testing additional files in Incremental source generator snapshot tests

[tm-nti]

I have read your awesome article on testing incremental generators:
https://andrewlock.net/creating-a-source-generator-part-2-testing-an-incremental-generator-with-snapshot-testing/

Which is great for testing compiled code, but in my use case I have some .json files I want to base the generated code on.
I am using the procedure described in the cookbook.
I managed to modify the testutil class (gist) and it seems to work

I mostly wish to know if there is a better way to do this, my modification feels dodgy and I am no expert on source generators

[sergey-shambir]

Thanks @tm-nti, I've implemented own source generator unit tests using your code example.

Result described here: https://gist.github.com/sergey-shambir/fb32a3011d8049b1b9ee76ed417ccc89