public void Return_False() { // Arrange var domainFactory = new Mock <IDomainFactory>(); var brandviserData = new Mock <IBrandviserData>(); var dateTimeProvider = new Mock <IDateTimeProvider>(); var whois = new Mock <IWhois>(); var txtRecordsChecker = new Mock <ITxtRecordsChecker>(); var mockedDomainsRepository = new Mock <IEfRepository <Domain> >(); mockedDomainsRepository.Setup(m => m.GetById(It.IsAny <int>())).Returns(new Domain() { BuyerId = "wrong id" }); brandviserData.Setup(b => b.Domains).Returns(mockedDomainsRepository.Object); var actualDomainId = 1; var actualbuyerId = "buyer id"; var domainService = new DomainService(brandviserData.Object, domainFactory.Object, dateTimeProvider.Object, whois.Object, txtRecordsChecker.Object); // Act var actualResult = domainService.CheckIfBuyerOwnsCertainDomain(actualDomainId, actualbuyerId); // Assert Assert.IsFalse(actualResult); }