Question

The EndToEnd test of my application includes loading the releasedlls by hand.

During testing i always have the following loaded:
– NUnit shadowcopy of n debug assemblies
– Postbuildeventcopy of n release assemblies

Even if i am sure that the two copies are from the same build generation (version) casting of my reflection loading fails.

to give a little bit of context here is some pseudo code:

private HookingHelper globalhooker;
private Tools.ISomething globalmockery;


TestfixtureSetUp(){
    globalhooker = new globalhooker();
    globalhooker.Loadfrom("c:\postbuildcopy.dll");
    globalmockery = Mockrepository.Generate<Tools.ISomething>();
    globalhooker.SetViaReflection<Tools.ISomething>("nameofsomething", globalmockery);
 }

I have a helper class which uses Loadfrom to get a static inside an assembly. Before i call anything i have to inject a mock.

This mock is created using the shadowcopy of a tools library in debug version since nunit creates it.

The loaded library is the release version, which is important to me since i want to do testing as close to the real environment as possible.

When i try to inject using reflection i have to use FieldInfo SetValue(...) the call looks something like this:

    public static void ReplaceFieldPublicStatic<T>(Type type, string fieldname, T obj)
    {
        FieldInfo field = AssemblyHelper.GetFieldInfoPublicStatic(type, fieldname);
        field.SetValue((T)obj, obj);
    }

Somethimes the Reflection works and sometimes my types can not be casted into each other.

The error is an ArgumentException generated by FieldInfo SetValue(...) .

When i inercept the exception and investigate the difference between field.FieldType != typeof(T) only the GetHashCode() call gives a different value.

I think there is a little bit of randomness involved.

Can i force the Typecast? Is that even wise?

Is there something i need to do while buildung my projects that i am missing?

Answer 1

Even if i am sure that the two copies are from the same build generation (version) casting of my reflection loading fails.

Yes – if two types have come from two different Assembly objects, they are different types as far as the CLR is concerned. The assemblies could have been loaded from the exact same byte sequences, but they’re still distinct assemblies.

Basically you’ll need to pick one Assembly to use for each type.