Xamarin SQLite单元测试64位窗口

Question

我正在开发一个使用SQLite数据库的Xamarin应用程序，我们有单元测试来覆盖这个功能。

这些单元测试、执行并在OS机器上传递，但是在Windows8(64位) VM上运行它们时，我们会看到与SQLite相关的错误(在out CI基础结构中充当从站)。

当测试运行时，我们看到的错误来自NUnit (2.6.4)

ProcessModel: Default    DomainUsage: Single
Execution Runtime: net-4.5
Unhandled Exception:
System.BadImageFormatException: Could not load file or assembly 'App.Core.Tests, Version=1.0.5900.25009, Culture=neutral, PublicKeyToken=null' or one of its dependencies. An attempt was made to load a program with an incorrect format.
File name: 'App.Core.Tests, Version=1.0.5900.25009, Culture=neutral, PublicKeyToken=null'

Server stack trace: 
at System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String  codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks)
at System.Reflection.RuntimeAssembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks)
at System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, RuntimeAssembly reqAssembly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks)
at System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, RuntimeAssembly reqAssembly, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks)
at System.Reflection.Assembly.Load(AssemblyName assemblyRef)
at NUnit.Core.Builders.TestAssemblyBuilder.Load(String path)
at NUnit.Core.Builders.TestAssemblyBuilder.Build(String assemblyName, Boolean autoSuites)
at NUnit.Core.Builders.TestAssemblyBuilder.Build(String assemblyName, String testName, Boolean autoSuites)
at NUnit.Core.TestSuiteBuilder.BuildSingleAssembly(TestPackage package)
at NUnit.Core.TestSuiteBuilder.Build(TestPackage package)
at NUnit.Core.SimpleTestRunner.Load(TestPackage package)
at NUnit.Core.ProxyTestRunner.Load(TestPackage package)
at NUnit.Core.ProxyTestRunner.Load(TestPackage package)
at NUnit.Core.RemoteTestRunner.Load(TestPackage package)
at System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage(IntPtr md, Object[] args, Object server, Object[]& outArgs)
at System.Runtime.Remoting.Messaging.StackBuilderSink.PrivateProcessMessage(RuntimeMethodHandle md, Object[] args, Object server, Object[]& outArgs)
at System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(IMessage msg)

Exception rethrown at [0]: 
 at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
 at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
 at NUnit.Core.TestRunner.Load(TestPackage package)
 at NUnit.Util.TestDomain.Load(TestPackage package)
 at NUnit.ConsoleRunner.ConsoleUi.Execute(ConsoleOptions options)
 at NUnit.ConsoleRunner.Runner.Main(String[] args)

这与使用64位窗口的事实有关吗？

Answer 1

BadImageFormat几乎总是因为正在运行的进程的位性与依赖程序集的位性之间存在不匹配。正如您可能知道的那样，Sqlite不是AnyCPU，而是x86或x64。很可能您的测试套件是编译的AnyCPU，但是您使用的是32位版本的Sqlite。

NUnit 3将自动检测测试套件的比特性(但不依赖程序集)，并正确运行它。NUnit 2不会，您必须相应地运行您的测试。来自NUnit 2.6的文档，

nunit控制台程序的.NET 2.0版本是使用/platform:anycpu构建的，这使得它在32位系统上被jit编译成32位代码，在64位系统上被编译为64位代码。当NUnit用于测试64位系统上的32位应用程序时，这会导致异常。为了避免这个问题，在64位系统上测试32位代码时，使用使用/platform:x86构建的nunit-console-x86程序。

写得不好，我们也许应该修复它，但我建议有两件事；

1. 确保您的测试程序集目标x86/x64与Sqlite匹配。
2. 如果您正在使用x86，请使用nunit-控制台-x86.exe运行您的测试。