Question

I was very happy with Moq until I needed to test a method that takes a delegate as parameter and got an UnsupportedException. The issue is also mentioned here and on Moq issue list.

Is there any framework that supports this kind of mocking?

For example:

/// 
/// Interfaces
///

public interface IChannelFactory<T> {
    TReturn UseService<TReturn>(Func<T, TReturn> function);
}

public interface IService {
    int Calculate(int i);
}

///
/// Test
///

Mock<IChannelFactory<IService>> mock = new Mock<IChannelFactory<IService>>();

// This line results in UnsupportedException
mock.Setup(x => x.UseService(service => service.Calculate(It.IsAny<int>()))).Returns(10);

Answer 1

I’m not quite sure what you’re trying to do, but this compiles and runs using your interfaces with Moq 4:

var mock = new Mock<IChannelFactory<IService>>();

mock.Setup(x => x.UseService(It.IsAny<Func<IService, int>>())).Returns(10);

int result = mock.Object.UseService(x => 0);

Console.WriteLine(result);  // prints 10

See also this answer for a more complex case.