In Robolectric Test, How To Wait For Messages In The Main Looper To Be Run?

I'm testing a Service using Robolectric 3. Once run, it registers an anonymous BroadcastReceive waits for the system to send a broadcast after some event occurred. In the test I in

Solution 1:

In Robolectric, the scheduler of a Service is normally in paused state. Any message that is put into the queue is not run until the time is not "advanced" by certain amount.

Given a Service myService, you can access its Robolectric scheduler and run its enqueued messages:

org.robolectric.util.Scheduler scheduler = shadowOf(myService.get().getMainLooper()).getScheduler();
while (!scheduler.advanceToLastPostedRunnable()) ;

// ... put your test assertions here

Please note that the shortcut Robolectric.flushForegroundThreadScheduler() only runs all the messages that were in the queue at that time; if any of those put other messages, they won't be executed.