public void ShowOverviewTest() { DataCreator dataCreate = new DataCreator(); var lines = new List <string> { "test1 10.10.2010 500 ", "test1 11.10.2010 600 ", "test2 12.10.2010 700 " }; dataCreate.LinesIntoData(lines); Overview oView = new Overview(); var result = oView.ShowOverview(new DateTime(2010, 10, 30), dataCreate.AllData); Assert.AreEqual(result, new List <string> { "test1: 500 EUR ", "test1: 600 EUR ", "test2: 700 EUR " }); }