A test for "BufferDebounce" to confirm how bursts are captured given particular timings

BufferDebounceTest.java

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

import java.util.List;
import java.util.concurrent.TimeUnit;

import rx.Observable;
import rx.observers.TestSubscriber;
import rx.schedulers.TestScheduler;
import rx.subjects.PublishSubject;
import rx.subjects.Subject;

@RunWith(JUnit4.class)
public class BufferDebounceTest {
    Subject<Integer, Integer> bursty;

    @Before
    public void setup() {
        bursty = PublishSubject.create();
    }

    @Test
    public void test() {
        // given
        TestScheduler testScheduler = new TestScheduler();

        Observable<Integer> burstyMulticast = bursty.publish().refCount();
        Observable<Integer> burstyDebounced = burstyMulticast.debounce(100, TimeUnit.MILLISECONDS, testScheduler);
        Observable<List<Integer>> burstyBuffered = burstyMulticast.buffer(burstyDebounced).filter(next -> next.size() >= 3);

        // when
        TestSubscriber<List<Integer>> testSubscriber = new TestSubscriber<>();
        burstyBuffered.subscribe(testSubscriber);

        // then
        bursty.onNext(1);
        bursty.onNext(1);
        bursty.onNext(1);
        bursty.onNext(1);
        testScheduler.advanceTimeBy(100, TimeUnit.MILLISECONDS);
        testSubscriber.assertValueCount(1);

        // then
        bursty.onNext(1);
        bursty.onNext(1);
        bursty.onNext(1);
        testScheduler.advanceTimeBy(99, TimeUnit.MILLISECONDS);
        bursty.onNext(1);
        testScheduler.advanceTimeBy(100, TimeUnit.MILLISECONDS);
        testSubscriber.assertValueCount(2);

        // then
        bursty.onNext(1);
        bursty.onNext(1);
        testScheduler.advanceTimeBy(100, TimeUnit.MILLISECONDS);
        testSubscriber.assertValueCount(2);
    }
}