public void ValidateRow_ValidRowTest_NoErrors(string rowString) { //preperation List <string> row = new List <string>(rowString.Split('|')); //Mock IOUtility var ioUtilityMock = new Mock <IOUtility>(); ioUtilityMock.Setup(i => i.ConvertDateToCulture("2018")).Returns("2018"); //prepare the variables DataReader reader = new AsciiReader(dataStructure, new AsciiFileReaderInfo(), ioUtilityMock.Object); IEnumerable <string> vairableNames = dataStructure.Variables.Select(v => v.Label); reader.SetSubmitedVariableIdentifiers(vairableNames.ToList()); //test List <Error> errors = reader.ValidateRow(new List <string>(row), 1); //asserts errors.Should().NotBeNull(); errors.Count.Should().Equals(0); }