.net - 在 C# 中测试静态类的扩展方法时，MSTest 抛出 ‘System.TypeInitializationException’

Question

我有一个名为 Helpers 的静态类，其中包含大量简单的辅助方法，包括“字符串”等的一些简单扩展方法:

public static string AddSquareBrackets(this string str)
{
     return "[" + str + "]";
}

我有一个测试类和方法如下:

[TestMethod()]
public void AddSquareBracketsTest()
{
     Assert.AreEqual("[NAME]", "NAME".AddSquareBrackets());
}

使用默认(无编码)构造函数声明的静态类:

namespace Equinoxe.Utilities.Helpers
{
    public static class HELPERS
    {

对 AddSquareBrackets 的调用会抛出以下错误:

System.TypeInitializationException was unhandled by user code
  Message=The type initializer for 'XXX.Utilities.Helpers.HELPERS' threw an exception.
  Source=XXX.Utilities
  TypeName=XXX.Utilities.Helpers.HELPERS
  StackTrace:
       at XXX.Utilities.Helpers.HELPERS.AddSquareBrackets(String str)
       at XXX.Utilities.Test.HELPERSTest.AddSquareBracketsTest() in C:\DEVELOPMENT\PROJECTS\XXX.NavEgate\XXX.Utilities.Test\HELPERSTest.cs:line 77
  InnerException: System.NullReferenceException
       Message=Object reference not set to an instance of an object.
       Source=XXX.Utilities
       StackTrace:
            at XXX.Utilities.Helpers.HELPERS..cctor() in C:\DEVELOPMENT\PROJECTS\XXX.Utilities\XXX.Utilities\Helpers\HELPERS.cs:line 44
       InnerException:{System.NullReferenceException: Object reference not set to an instance of an object.
   at XXX.Utilities.Helpers.HELPERS..cctor() in C:\DEVELOPMENT\PROJECTS\XXX.Utilities\XXX.Utilities\Helpers\HELPERS.cs:line 44}

我也看过

我正在运行 VS2010

Answer 1

添加断点:

C:\DEVELOPMENT\PROJECTS\XXX.Utilities\XXX.Utilities\Helpers\HELPERS.cs:第 44 行

在那一行，有些东西是 null，这不应该是。