public void Given_Survey_Exists_When_I_Call_GetInstallDate_The_Correct_Date_Is_Returned() { //arrange var installDate = DateTime.Today; const string instrumentName = "Instrument1"; var survey1Mock = new Mock <ISurvey>(); survey1Mock.Setup(s => s.Name).Returns(instrumentName); survey1Mock.Setup(s => s.InstallDate).Returns(installDate); var surveyItems = new List <ISurvey> { survey1Mock.Object }; _surveyCollectionMock = new Mock <ISurveyCollection>(); _surveyCollectionMock.Setup(s => s.GetEnumerator()).Returns(() => surveyItems.GetEnumerator()); _serverParkMock.Setup(s => s.Surveys).Returns(_surveyCollectionMock.Object); //act var result = _sut.GetInstallDate(_connectionModel, instrumentName, _serverParkName); //assert Assert.IsNotNull(result); Assert.AreEqual(installDate, result); }