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 2008内置单元测试框架的优点/变化:

The 2008 version now is available in professional editions (before it required expensive versions of Visual Studio, and this is just for developer unit testing) that left a lot of developers with the only choice of open/external testing frameworks. Built-in API supported by a single company. Use the same tools to to run and create tests (you may run them using the command line also MSTest). Simple design (granted without a mock framework, but this is a great starting point for many programmers). Long term support granted (I still remember what happened to NDoc, and I don't want to commit to a testing framework that might not be supported in five years, but I still consider NUnit a great framework). If using Team Foundation Server as your backend, you can create work items or bugs with the failed test data in a simple fashion.

xUnit是新项目的另一种可能。它的语法可能更直观，但它与其他框架并不兼容。

我从MSTest开始，但我因为一个简单的原因而改变了。MSTest不支持从其他程序集继承测试方法。

我讨厌多次编写相同的测试。特别是在一个大型项目中，测试方法可以很容易地运行到100个测试。

NUnit正是我所需要的。NUnit唯一缺少的是Visual Studio插件，它可以显示每个测试的红色/绿色状态(就像VSTS一样)。

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。

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。