Get Current Activity in Espresso android

In Espresso, you can use ActivityLifecycleMonitorRegistry but it is not officially supported, so it may not work in future versions.

Here is how it works:

Activity getCurrentActivity() throws Throwable {
  getInstrumentation().waitForIdleSync();
  final Activity[] activity = new Activity[1];
  runTestOnUiThread(new Runnable() {
    @Override
    public void run() {
      java.util.Collection<Activity> activities = ActivityLifecycleMonitorRegistry.getInstance().getActivitiesInStage(Stage.RESUMED);
      activity[0] = Iterables.getOnlyElement(activities);
  }});
  return activity[0];
}