.NET Moq mock internal类型

问题

Can not create proxy for type xxx because type xxx is not accessible. Make it public, or internal and mark your assembly with [assembly: InternalsVisibleTo("DynamicProxyGenAssembly2, PublicKey=0024000004800000940000000602000000240000525341310004000001000100c547cac37abd99c8db225ef2f6c8a3602f3b3606cc9891605d02baa56104f4cfc0734aa39b93bf7852f7d9266654753cc297e7d2edfe0bac1cdcf9f717241550e0a7b191195b7667bb4f64bcb8e2121380fd1d9d46ad2d92d2d15605093924cceaf74c4861eff62abf69b9291ed0a340e113be11e6a7d3113e92484cf7045cc7")] attribute, because assembly Microsoft.Extensions.Logging.Abstractions is strong-named. (Parameter 'interfaceToProxy')
    at Castle.DynamicProxy.DefaultProxyBuilder.AssertValidTypeForTarget(Type type, Type target, String paramName)
   at Castle.DynamicProxy.DefaultProxyBuilder.AssertValidTypeForTarget(Type type, Type target, String paramName)
   at Castle.DynamicProxy.DefaultProxyBuilder.AssertValidType(Type target, String paramName)
   at Castle.DynamicProxy.DefaultProxyBuilder.CreateInterfaceProxyTypeWithoutTarget(Type interfaceToProxy, Type[] additionalInterfacesToProxy, ProxyGenerationOptions options)
   at Castle.DynamicProxy.ProxyGenerator.CreateInterfaceProxyTypeWithoutTarget(Type interfaceToProxy, Type[] additionalInterfacesToProxy, ProxyGenerationOptions options)
   at Castle.DynamicProxy.ProxyGenerator.CreateInterfaceProxyWithoutTarget(Type interfaceToProxy, Type[] additionalInterfacesToProxy, ProxyGenerationOptions options, IInterceptor[] interceptors)
   at Moq.CastleProxyFactory.CreateProxy(Type mockType, IInterceptor interceptor, Type[] interfaces, Object[] arguments) in C:\projects\moq4\src\Moq\Interception\CastleProxyFactory.cs:line 50

解决方法

.NET Framework以及.NET(Core) 5之前的版本

在AssemblyInfo.cs文件里添加 InternalsVisibleTo 声明

// This assembly is the default dynamic assembly generated by Castle DynamicProxy,
// used by Moq. If your assembly is strong-named, paste the following in a single line:
[assembly:InternalsVisibleTo("DynamicProxyGenAssembly2,PublicKey=0024000004800000940000000602000000240000525341310004000001000100c547cac37abd99c8db225ef2f6c8a3602f3b3606cc9891605d02baa56104f4cfc0734aa39b93bf7852f7d9266654753cc297e7d2edfe0bac1cdcf9f717241550e0a7b191195b7667bb4f64bcb8e2121380fd1d9d46ad2d92d2d15605093924cceaf74c4861eff62abf69b9291ed0a340e113be11e6a7d3113e92484cf7045cc7")]

// Or, if your own assembly is not strong-named, omit the public key:
[assembly:InternalsVisibleTo("DynamicProxyGenAssembly2")]

参考：https://github.com/devlooped/moq/wiki/Quickstart

.NET 5以后的版本

.NET 5以后默认不再生成AssemblyInfo.cs文件，因此需要在项目的csproj文件里添加InternalsVisibleTo配置

   <ItemGroup>
       <InternalsVisibleTo Include="DynamicProxyGenAssembly2, PublicKey=0024000004800000940000000602000000240000525341310004000001000100c547cac37abd99c8db225ef2f6c8a3602f3b3606cc9891605d02baa56104f4cfc0734aa39b93bf7852f7d9266654753cc297e7d2edfe0bac1cdcf9f717241550e0a7b191195b7667bb4f64bcb8e2121380fd1d9d46ad2d92d2d15605093924cceaf74c4861eff62abf69b9291ed0a340e113be11e6a7d3113e92484cf7045cc7" />
   </ItemGroup>

参考链接

• https://github.com/devlooped/moq/wiki/Quickstart
• https://learn.microsoft.com/en-us/dotnet/core/project-sdk/msbuild-props#internalsvisibleto