Question

I’m trying to create a mock HttpContextBase for unit test.

var fakePrinciple = new GenericPrincipal(
           new GenericIdentity(userId), 
           rolesList.ToArray());            
var mockHttpContext = new Mock<HttpContextBase>();
mockHttpContext.Setup(t => t.User).Returns(fakePrinciple);
HttpContextBase mockedContext = mockHttpContext.Object;

The unit test fails at the last statement with

threw exception:
System.ArgumentException: Unable to
obtain public key for
StrongNameKeyPair..

System.Reflection.StrongNameKeyPair.nGetPublicKey(Boolean
exported, Byte[] array, String
container)
System.Reflection.StrongNameKeyPair.get_PublicKey()
System.AppDomain.InternalDefineDynamicAssembly(AssemblyName
name, AssemblyBuilderAccess access,
String dir, Evidence evidence,
PermissionSet requiredPermissions,
PermissionSet optionalPermissions,
PermissionSet refusedPermissions,
StackCrawlMark& stackMark,
IEnumerable`1
unsafeAssemblyAttributes)
System.AppDomain.DefineDynamicAssembly(AssemblyName
name, AssemblyBuilderAccess access)
Castle.DynamicProxy.ModuleScope.CreateModule(Boolean
signStrongName)
Castle.DynamicProxy.ModuleScope.ObtainDynamicModuleWithStrongName()
Castle.DynamicProxy.ModuleScope.ObtainDynamicModule(Boolean
isStrongNamed)
Castle.DynamicProxy.Generators.Emitters.ClassEmitter.CreateTypeBuilder(ModuleScope
modulescope, String name, Type
(blah blah snip)

I googled and the suggestions here don’t seem to work (change RSA folder security setting etc) http://groups.google.com.br/group/castle-project-users/browse_thread/thread/85685cf32a795158

Am I correct to think that because HttpContextBase is part of System.Web.Abstraction, which is a signed assembly. Moq will actually attempt to sign the dynamic assembly, and fail?

Answer 1

MoQ uses Castle DynamicProxy for generating mocks at runtime. Rhino Mocks uses the same library for the same purpose. If you check here:

http://ayende.com/Blog/archive/2006/06/09/UnableToObtainPublicKeyForStrongNameKeyPair.aspx

you’ll see that the issue is one of permissions to the machine key store. Whatever user account is running the test must have permission to create and delete keys in the store.

You can find much more details about this issue here:
http://groups.google.co.uk/group/RhinoMocks/browse_thread/thread/26df68ff01567509/5ddebf407228edc4