Visual Studio's Preview Code does not actually do anything. Exception thrown in my log was: [09/17 12:42:00,devenv.exe(6808:1),Error] CodeGenerator.GenerateTestMethodInt() : EXCEPTION! (see below) Situation: CodeGeneration Outer Exception Type: System.InvalidCastException Message: Unable to cast object of type 'ArtOfTest.Common.Design.CodeGeneration.NonBound' to type 'ArtOfTest.Common.Design.CodeGeneration.DataBound'. HRESULT: 0x80004002 (Official ID (if app.) = COR_E_INVALIDCAST, Error Bit = FAILED, Facility = FACILITY_NULL, Code = 16386) Call Stack: at ArtOfTest.WebAii.Design.IntrinsicTranslators.Descriptors.VisibleVerificationDescriptor.ToCode() at ArtOfTest.Common.Design.CodeGeneration.CodeGenerator.GenerateTestMethodInt(Test test, CodeGenerationLanguage codeLanguage, UnitTestType unitTestType, Boolean codePreview, String dataFileName, List`1& requiredReferences, Action`1 techSpecificInitialization)