examples or vignette for shinytest with learnr

Hi, I know that shinytest use has been added to learnr, but I am at a loss of how to actually use it.
My main need is to check the functioning of specific chunks inside tutorials that reside in a package. I want to check if the correct objects are available to a chunk (as created in a setup chunk or the general setup of the tutorial), whether images that should be showed in the tutorial are indeed available in their images folder, or whether some separate functions in the package yield the correct output.

I also want to check some of the quizzes, but my main testing need is what I write above. Since my package is in active development, as are the tutorials inside my package, there are too many moving parts to be able to track the working of my tutorials manually.

Although I know that it is possible to use shinytest to unit test tutorials, I really would like to see examples of how this can be done in practice. It would be brilliant if a vignette could be added to the package, or a separate entry on Interactive Tutorials for R.
Can anyone share actual examples of how shinytest (or another framework) can be used to maintain the integrity of learnr tutorials?

thanks!