visual-studio-2008 - 为什么在同一测试项目程序集中两次调用[AssemblyInitialize]和[AssemblyCleanup]？

Question

我认为这些属性的全部目的是每个程序集仅运行一次。我有一个简单的类，如下所示:

[TestClass]
public class AssemblyIntegrationTestSetup
{
    public AssemblyIntegrationTestSetup() { }
    public TestContext TestContext { get; set; }

    [AssemblyInitialize]
    public static void SetupIntegrationTests(TestContext context)
    {
         WindowsServiceService.Instance.StartService("Distributed Transaction Coordinator");
    }

    [AssemblyCleanup]
    public static void TeardownIntegrationTests()
    {
          WindowsServiceService.Instance.StopService("Distributed Transaction Coordinator");
    }

}

但是，当我运行测试套件时，程序集级的Initialize和Cleanup方法执行两次。以下是有关我的环境的详细信息:

所有测试类都在同一项目/程序集中。

我有按 namespace 分隔的集成和单元测试。

对于集成测试，我使用MSTextExtensions允许回滚数据库事务。

我也正在启动/停止MS SQL Server DTC服务，这是回滚功能所必需的。我希望每个测试套件运行一次(并且发现的最佳折衷方法是使用程序集级属性)。该代码可以工作，但是执行两次。

如果很重要，我的一些测试中还将使用Microsoft Moles Framework。

观察到的行为类似于:

AssemblyInitialize         

Class1.TestInitialize
Class1.TestMethod1
Class1.TestCleanup

AssemblyInitalize         <-- //This shouldn't be happening right?

Class2.TestInitialize
Class2.TestMethod1
Class2.TestCleanup

Class2.TestInitialize
Class2.TestMethod2
Class2.TestCleanup

Class5.TestInitialize
Class5.TestMethod1
Class5.TestCleanup

Class7.TestInitialize
Class7.TestMethod1
Class7.TestCleanup

//More random bouncing around then...

AssemblyCleanup 
AssemblyCleanup           <-- //This shouldn't be happening right?

Answer 1

从MSDN库文章:

Important

This attribute should not be used on ASP.NET unit tests, that is, any test with [HostType("ASP.NET")] attribute. Because of the stateless nature of IIS and ASP.NET, a method decorated with this attribute might be called more than once per test run.

您可以在测试运行器中调整一些旋钮。我只是用一个计数器来解决这个问题:

private int InitCount;

[AssemblyInitialize]
public static void SetupIntegrationTests(TestContext context)
{
     if (InitCount++ == 0) {
         WindowsServiceService.Instance.StartService("Distributed Transaction Coordinator");
     }
}

[AssemblyCleanup]
public static void TeardownIntegrationTests()
{
      if (--InitCount == 0) {
          WindowsServiceService.Instance.StopService("Distributed Transaction Coordinator");
      }
}