is there a way to override Dispatchers.UI on unit tests in android? it's trying to use Looper.getMainLooper() which is a stubbed method

Do not use Dispatcher.UI directly, instead pass it as dependency of your coroutine scope

I'm not using it, it's because of this line:

Your test subject shouldn't hard-code

Dispatchers.UI

. You should inject a dispatcher so you can pass a different one in from your unit tests.