I was actually offered a Bachelor thesis topic by a company to write a test bench for a product in LabView.
From what they told me and my other engineering experience I’d suggest going with an approach similar to what’s used with HDLs. For unit tests create test benches in the language itself which call the functions you want to test with a predefined input (e.g. from a file) and then analyse and save the output.
You can extend this to obtaining other information as well, but tbh I’ll bet it’s still gonna be a pain.
Hope that helps at least a little.
A shocking amount of microcontroller manufacturers have eclipse based IDEs for their chips. Thought that seems to be going out of style, luckily.