public async void TestInsertAsync() { Mock <IUnitOfWork> uowMock = new Mock <IUnitOfWork>(); Mock <IRepository <Post> > repoMock = new Mock <IRepository <Post> >(); repoMock.Setup(x => x.AddAsync(It.IsAny <Post>())).Returns(Task.FromResult(true)); SomeService service = new SomeService(uowMock.Object, repoMock.Object); await service.InsertAsync("TestInsertAsync"); repoMock.Verify(m => m.AddAsync(It.IsAny <Post>()), Times.Once()); }