public void SetUpTests() { var surveyDayMock = new Mock <ISurveyDay>(); surveyDayMock.Setup(d => d.Date).Returns(_surveyDay); var surveyDays = new List <ISurveyDay> { surveyDayMock.Object }; _surveyDayCollection = new Mock <ISurveyDayCollection>(); _surveyDayCollection.Setup(s => s.GetEnumerator()).Returns(surveyDays.GetEnumerator()); _catiManagementServerMock = new Mock <IRemoteCatiManagementServer>(); _catiManagementServerMock.Setup(c => c.LoadCatiInstrumentManager(It.IsAny <string>()).CreateDaybatch(It.IsAny <DateTime>())); _catiManagementServerMock.Setup(c => c.LoadCatiInstrumentManager(It.IsAny <string>()).Specification.SurveyDays).Returns(_surveyDayCollection.Object); _catiProviderMock = new Mock <IRemoteCatiManagementServerProvider>(); _catiProviderMock.Setup(r => r.GetCatiManagementForServerPark(_connectionModel, _serverParkName)) .Returns(_catiManagementServerMock.Object); _surveyServiceMock = new Mock <ISurveyService>(); //setup service under test _sut = new CatiService(_catiProviderMock.Object, _surveyServiceMock.Object); }