Frontend unit testing with Mink
As of 5.34.0 integration with the Mink frontend testing framework is available. I've tried to emphasize that you can use this without knowing Drupal in terms of testing contribution pages, events, etc. There's maybe a little too much handholding in here but I also looked at a workflow using buildkit but then you still have some issues and still have extra bits you need to download.
FYI @KarinG, and at the end it links to your SE post too.