unit-testing – 检索SelectList项的计数？

我有一个返回SelectList的HtmlHelper方法：

public static SelectList FilterSelectList(this HtmlHelper helper, List<Stuff> eList, string dept)
{
 List<Stuff> returnList = new List<Stuff>();

 //Do Stuff    

 return new SelectList(returnList, "ID", "Name");
}

然后我进行了测试,确认过滤器已正确完成：

// Arrange
List<Stuff> eList = MVCMocks.GetList();
string dept = "T";
int expectedCount = eList.FindAll(e => e.Dept == dept).Count;

// Act
var actual = HtmlHelpers.FilterSelectList(helper, eList, dept);

// Assert
Assert.AreEqual(expectedCount, actual.Count, "The list was not properly filtered.");

调用actual.Count会导致错误.

我希望这只是我的一个愚蠢疏忽的例子,但我一直在敲打这个问题.证明我是对的！