@Test
  public void testLoadAndSaveAggregate() {
    UUID identifier = UUID.randomUUID();
    DomainEventMessage event1 =
        new GenericDomainEventMessage<String>(
            identifier, (long) 1, "Mock contents", MetaData.emptyInstance());
    DomainEventMessage event2 =
        new GenericDomainEventMessage<String>(
            identifier, (long) 2, "Mock contents", MetaData.emptyInstance());
    when(mockEventStore.readEvents("test", identifier))
        .thenReturn(new SimpleDomainEventStream(event1, event2));

    TestAggregate aggregate = testSubject.load(identifier, null);

    assertEquals(0, aggregate.getUncommittedEventCount());
    assertEquals(2, aggregate.getHandledEvents().size());
    assertSame(event1, aggregate.getHandledEvents().get(0));
    assertSame(event2, aggregate.getHandledEvents().get(1));

    // now the aggregate is loaded (and hopefully correctly locked)
    StubDomainEvent event3 = new StubDomainEvent();

    aggregate.apply(event3);

    CurrentUnitOfWork.commit();

    verify(mockEventBus).publish(isA(DomainEventMessage.class));
    verify(mockEventBus, never()).publish(event1);
    verify(mockEventBus, never()).publish(event2);
    verify(mockEventStore, times(1)).appendEvents(eq("test"), isA(DomainEventStream.class));
    assertEquals(0, aggregate.getUncommittedEventCount());
  }
  @Test
  public void testLoadEventsWithDecorators() {
    UUID identifier = UUID.randomUUID();
    SpyEventPreprocessor decorator1 = new SpyEventPreprocessor();
    SpyEventPreprocessor decorator2 = new SpyEventPreprocessor();
    testSubject.setEventStreamDecorators(Arrays.asList(decorator1, decorator2));
    when(mockEventStore.readEvents("test", identifier))
        .thenReturn(
            new SimpleDomainEventStream(
                new GenericDomainEventMessage<String>(
                    identifier, (long) 1, "Mock contents", MetaData.emptyInstance()),
                new GenericDomainEventMessage<String>(
                    identifier, (long) 2, "Mock contents", MetaData.emptyInstance()),
                new GenericDomainEventMessage<String>(
                    identifier, (long) 3, "Mock contents", MetaData.emptyInstance())));
    TestAggregate aggregate = testSubject.load(identifier);
    // loading them in...
    InOrder inOrder = Mockito.inOrder(decorator1.lastSpy, decorator2.lastSpy);
    inOrder.verify(decorator2.lastSpy).next();
    inOrder.verify(decorator1.lastSpy).next();

    inOrder.verify(decorator2.lastSpy).next();
    inOrder.verify(decorator1.lastSpy).next();

    inOrder.verify(decorator2.lastSpy).next();
    inOrder.verify(decorator1.lastSpy).next();
    aggregate.apply(new StubDomainEvent());
    aggregate.apply(new StubDomainEvent());
  }
  @Test
  public void testLoadAndSaveWithConflictingChanges() {
    ConflictResolver conflictResolver = mock(ConflictResolver.class);
    UUID identifier = UUID.randomUUID();
    DomainEventMessage event2 =
        new GenericDomainEventMessage<String>(
            identifier, (long) 2, "Mock contents", MetaData.emptyInstance());
    DomainEventMessage event3 =
        new GenericDomainEventMessage<String>(
            identifier, (long) 3, "Mock contents", MetaData.emptyInstance());
    when(mockEventStore.readEvents("test", identifier))
        .thenReturn(
            new SimpleDomainEventStream(
                new GenericDomainEventMessage<String>(
                    identifier, (long) 1, "Mock contents", MetaData.emptyInstance()),
                event2,
                event3));
    testSubject.setConflictResolver(conflictResolver);
    TestAggregate actual = testSubject.load(identifier, 1L);
    verify(conflictResolver, never())
        .resolveConflicts(anyListOf(DomainEventMessage.class), anyListOf(DomainEventMessage.class));
    final StubDomainEvent appliedEvent = new StubDomainEvent();
    actual.apply(appliedEvent);

    CurrentUnitOfWork.commit();

    verify(conflictResolver)
        .resolveConflicts(payloadsEqual(appliedEvent), eq(Arrays.asList(event2, event3)));
  }
  @Test
  public void testSaveEventsWithDecorators() {
    SpyEventPreprocessor decorator1 = new SpyEventPreprocessor();
    SpyEventPreprocessor decorator2 = new SpyEventPreprocessor();
    testSubject.setEventStreamDecorators(Arrays.asList(decorator1, decorator2));
    testSubject.setEventStore(
        new EventStore() {
          @Override
          public void appendEvents(String type, DomainEventStream events) {
            while (events.hasNext()) {
              events.next();
            }
          }

          @Override
          public DomainEventStream readEvents(String type, Object identifier) {
            return mockEventStore.readEvents(type, identifier);
          }
        });
    UUID identifier = UUID.randomUUID();
    when(mockEventStore.readEvents("test", identifier))
        .thenReturn(
            new SimpleDomainEventStream(
                new GenericDomainEventMessage<String>(
                    identifier, (long) 3, "Mock contents", MetaData.emptyInstance())));
    TestAggregate aggregate = testSubject.load(identifier);
    aggregate.apply(new StubDomainEvent());
    aggregate.apply(new StubDomainEvent());

    CurrentUnitOfWork.commit();

    InOrder inOrder = Mockito.inOrder(decorator1.lastSpy, decorator2.lastSpy);
    inOrder.verify(decorator1.lastSpy).next();
    inOrder.verify(decorator2.lastSpy).next();

    inOrder.verify(decorator1.lastSpy).next();
    inOrder.verify(decorator2.lastSpy).next();
  }