public async Task SaveChanges() { var dotaHelperData = new Mock <IDotaHelperData>(); var users = new Mock <IDotaHelperRepository <DotaHelperUser> >(); var postedGuides = new Mock <List <Guide> >(); var user = new DotaHelperUser { PostedGuides = postedGuides.Object }; users.Setup(x => x.FindAsync(It.IsAny <string>())).Returns(Task.FromResult(user)); var userGuides = new Mock <IDotaHelperRepository <DotaHelperUserGuide> >(); var guides = new Mock <IGuideData>(); dotaHelperData.Setup(x => x.Users).Returns(users.Object); dotaHelperData.Setup(x => x.Guides).Returns(guides.Object); dotaHelperData.Setup(x => x.UserGuides).Returns(userGuides.Object); var heroesProvider = new Mock <IHeroesProvider>(); var itemsProvider = new Mock <IItemsProvider>(); var mapper = new Mock <IMapper>(); var guideService = new GuidesService(dotaHelperData.Object, heroesProvider.Object, itemsProvider.Object, mapper.Object); await guideService.AddGuide("1", new GuidePostDataModel()); dotaHelperData.Verify(x => x.SaveChangesAsync(), Times.Once); }