单元测试框架实际上并不重要，因为你可以用单独的项目文件和条件编译转换测试类(就像这样，Visual Studio→NUnit):

 #if !NUNIT
  using Microsoft.VisualStudio.TestTools.UnitTesting;
 #else
  using NUnit.Framework;
  using TestClass = NUnit.Framework.TestFixtureAttribute;
  using TestMethod = NUnit.Framework.TestAttribute;
  using TestInitialize = NUnit.Framework.SetUpAttribute;
  using TestCleanup = NUnit.Framework.TearDownAttribute;
  using TestContext = System.String;
  using DeploymentItem = NUnit.Framework.DescriptionAttribute;
 #endif

TestDriven。Net插件很好，不是很贵…对于普通的Visual Studio 2008，你必须从你的测试类或测试列表中找到测试。TestDriven。Net中，您可以直接从正在测试的类中运行测试。毕竟，单元测试应该易于维护，并且离开发人员很近。

Daok列出了Visual Studio 2008测试项目的所有优点。下面是NUnit的优点。

NUnit has a mocking framework. NUnit can be run outside of the IDE. This can be useful if you want to run tests on a non-Microsoft build server, like CruiseControl.NET. NUnit has more versions coming out than visual studio. You don't have to wait years for a new version. And you don't have to install a new version of the IDE to get new features. There are extensions being developed for NUnit, like row-tests, etc. Visual Studio tests take a long time to start up for some reason. This is better in Visual Studio 2008, but it is still too slow for my taste. Quickly running a test to see if you didn't break something can take too long. NUnit with something like Testdriven.Net to run tests from the IDE is actually much faster. Especially when running single tests. According to Kjetil Klaussen, this is caused by the Visual Studio testrunner. Running MSTest tests in TestDriven.Net makes MSTest performance comparable to NUnit.

我已经使用NUnit两年了。一切都很好，但是我不得不说Visual Studio中的单元测试系统非常好，因为它在GUI中，可以更容易地对私有函数进行测试，而不必搞得乱七八糟。

此外，Visual Studio的单元测试允许你做覆盖和其他NUnit单独不能做的事情。

据我所知，目前。net有四个可用的单元测试框架:

NUnit 运行工具 MSTest xUnit

NUnit一直处于领先地位，但在过去一年左右，这种差距已经缩小。我自己还是更喜欢NUnit，特别是他们不久前添加了一个流畅的界面，这使得测试非常易读。

如果您刚刚开始进行单元测试，这可能没有太大区别。一旦你跟上了进度，你就能更好地判断哪个框架最适合你的需求。

MSTest is essentially NUnit slightly reworked, with a few new features (such as assembly setup and teardown, not just fixture and test level), and missing some of the best bits (such as the new 2.4 constraint syntax). NUnit is more mature, and there is more support for it from other vendors; and of course since it's always been free (whereas MSTest only made it into the Professional version of Visual Studio 2008, and before that it was in way more expensive SKUs), and most ALT.NET projects use it.

话虽如此，还是有一些公司非常不愿意使用没有微软标签的东西，尤其是OSS代码。因此，拥有官方的微软测试框架可能是这些公司需要进行测试的动机;老实说，重要的是测试，而不是你使用什么工具(使用Tuomas Hietanen的代码，你几乎可以让你的测试框架可互换)。

Visual Studio测试框架的一个小麻烦是，它会创建许多测试运行文件，这些文件往往会使您的项目目录变得混乱——尽管这并不是什么大问题。

另外，如果你缺少一个像TestDriven这样的插件。NET，你不能在Visual Studio环境中调试你的NUnit(或MbUnit, xUnit等)单元测试，而你可以在Microsoft Visual Studio测试框架中进行，这是内置的。