Migrating Junit4 tests to androidx: What causes 'delegate runner could not be loaded'?

Question

I am migrating my app to androidx, I can\'t seem to get my unit tests working. I took example from Google\'s AndroidJunitRunnerSample, which has been updated to use the new

Answer 1

For me the problem was the @Rule annotation..
I don't know the cause for now.

As a temporary workaround yo can for example start your activity using UIAutomator for ActivityTestRule.