InternalsVisibleTo useful

One of the not so commonly usage attributes targeting assemblies is the InternalsVisibleTo attribute. This attribute declares that a given assembly will be given access to internal items in the assembly it is declared on.

This can be very useful with unit testing if you want to have access to internal items or in scenarios were you want to create a new assembly as a wrapper around one of your existing assemblies you may want to give it those privileges. A good place to stick this in is the AssemblyInfo.cs class with usage as shown below. By using this feature you create what can be called Friend libraries.

[assembly: InternalsVisibleTo("TargetAssembly, PublicKey=")]