UI Test shards are flaky, perhaps interfering with each other?

[rjrjr]

UI Test shards are flaky, perhaps interfering with each other?

[steve-the-edwards]

For example, #1105 added a new test class but did not invoke it. Making no changes to code that would be executed in CI. But yet the instrumentation shards all failed? Such as https://github.com/square/workflow-kotlin/actions/runs/6051263654.

We have no idea why they fail - but they look like legit timeouts on espresso, so are the emulators freezing/lagging?

[rjrjr]

Maybe we have some good old espresso root matcher issues? Maybe a system dialog was popped? This would be easier to dig into if we had screen grabs or video. And if I had a pony.

com.squareup.workflow1.ui.container.BackStackContainerPersistenceLifecycleTest > restores_view_on_pop_after_config_change[test(AVD) - 10] FAILED 
	androidx.test.espresso.base.RootViewPicker$RootViewWithoutFocusException: Waited for the root of the view hierarchy to have window focus and not request layout for 10 seconds. If you specified a non default root matcher, it may be picking a root that never takes focus. Root:
	Root{application-window-token=android.view.ViewRootImpl$W@8a45edf, window-token=android.view.ViewRootImpl$W@8a45edf, has-window-focus=false, layout-params-type=1, layout-params-string={(0,0)(fillxfill) sim={forwardNavigation} ty=BASE_APPLICATION wanim=0x10302fe