internalsvisibleto

I understand that the InternalVisibleTo attribute is used to expose types and methods with the internal access modifier to a specified assembly. I have only ever used this for exposing internal methods to a separate assembly containing a suite of unit tests. I am struggling to think of another scenario when this should be used. Was this attribute introduced specifically to aid unit testing or was there another reason? A scenario can be that you have separation of logic between assemblies (like internal data objects and the logic layer). You don't want to expose the classes to your users, but

I am trying to use the InternalsVisibleTo assembly attribute to make my internal classes in a .NET class library visible to my unit test project. For some reason, I keep getting an error message that says: 'MyClassName' is inaccessible due to its protection level Both assemblies are signed and I have the correct key listed in the attribute declaration. Any ideas? Joe Are you absolutely sure you have the correct public key specified in the attribute? Note that you need to specify the full public key, not just the public key token. It looks something like: [assembly: InternalsVisibleTo(