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

The testing framework actually give too little information. I encountered the same issue and dug into the stack trace, and found these validation:

So you must declare your @BeforeClass method static.