Xamarin SQLite Unit Testing 64-Bit Windows

Question

我正在开发一个使用 SQLite 数据库的 Xamarin 应用程序，我们有单元测试来涵盖此功能。

这些单元测试在OS X机器上执行和传递，但是在Windows 8（64位）VM上运行它们时，我们会看到SQLite相关的错误（这充当CI基础架构中的从属服务器）。

我们看到的错误来自测试运行时的 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数与依赖程序集的位数不匹配。你可能知道，Sqlite不是AnyCPU，而是x86或x64。您的测试套件很可能是编译为 AnyCPU，但您使用的是 32 位版本的 Sqlite。

NUnit 3 将自动检测测试套件（但不是依赖程序集）的位数并正确运行它。NUnit 2 不会，您必须相应地运行测试。从 NUnit 2.6 文档中，

nunit-console 程序的 .NET 2.0 版本是使用/platform：anycpu 构建的，这导致它在 32 位系统上被 jit 编译为 32 位代码，在 64 位系统上被 jit 编译为 64 位代码。当 NUnit 用于在 64 位系统上测试 32 位应用程序时，这会导致异常。若要避免此问题，请在 64 位系统上测试 32 位代码时使用 nunit-console-x86 程序，该程序是使用/platform：x86 构建的。

写得不好，我们可能应该修复它，但我会推荐两件事;

1. 确保您的测试程序集面向 x86/x64 以匹配 Sqlite
如果您使用的是 x86
2. ，请使用 nunit-console-x86 运行测试.exe