public async Task Shoud_Add_CandidateTest_In_CandidateService() { var candidate = new Candidate() { FirstName = "Minamba", LastName = "Camara", Test = new TestModel() { Title = "c#" } }; var mockRepository = Substitute.For <ICandidatesRepository>(); var logger = Substitute.For <ILog>(); mockRepository.AddCandidateTestAsync(candidate).Returns(candidate); var candidateService = new CandidatesService(mockRepository, logger); var result = await candidateService.AddCandidateTestAsync(candidate); Assert.AreEqual(candidate, result); }