I firmly believe in TDD and have a lot of experience writing functional integration frameworks and system testing frameworks. I am used to writing unit tests for the system test infrastructure (general code, helper classes, test tools, etc.). But I am not very well acquainted with the latest UI tests with Selenium WebDriver. I understand the page object design pattern and its advantages. And so it seems, of course, that you want to unit-test your page objects in the same way you want to use helper classes and tooling for non-UI unit testing.
But after a long search it seems that this topic hardly ever appears. And I can not find any good advice on how to tackle that. Is that because people simply do not test their UI test infrastructure? Or is it that so few people do it that nobody bothers to write articles about it? And can you recommend articles about things you should or should not do? Some of the best questions I've found online are now 6 to 8 years old, and it seems that this approach has now become established.
This is meant to be a language independent question, but if relevant, we will use Python, PyTest, and the Pytest Selenium plugin in my current project.