So I recently started messing around with Espresso in one of my existing Android projects.
Everything went pretty decently, until I came to find AutoCompleteTextView in my program. I don't seem to understand how to properly click the first thing in the autocomplete list. I'm actually not even sure which to use, onView() or onData() in this instance.
So i finally figured it out, thanks to this previous question: Testing autocomplete textview using espresso tool
Ill just post my version of it for people who might use it in future.
onData(instanceOf("Whatever your arrayadapter contains".class)).inRoot(RootMatchers.withDecorView(not(is(mActivityRule.getActivity().getWindow().getDecorView())))).perform(ViewActions.click());