How to rotate activity, I mean: screen orientation change using Espresso?

Question

I have decided that one of the testing criteria for my application tests with Google\'s Espresso is:

Test should maintain Activity state after s

Answer 1

This more complete solution creates a custom Espresso ViewActionand works well. It shows how to get the Activity (even when it is an AppCompatActivity) before calling its setRequestedOrientation() method. It also has a clean caller interface:

onView(isRoot()).perform(orientationLandscape()); 
onView(isRoot()).perform(orientationPortrait());

I follow each orientation change with a 100 ms delay, though you may not need it.