using System;

using Moq;

using AssertLibrary;

​

public class Program

{

    public static void Main()

    {

        var unittest =  new Unittests();

        unittest.Run();

    }

}

​

public class Unittests

{   

    public void Run()

    {

        // Arrange

        var cacheMock = new Mock<ICache>();

        cacheMock

            .Setup(c => c.GetOrSet<MyModel>(It.IsAny<string>(), It.IsAny<Func<MyModel>>()))

            .Returns((string key, Func<MyModel> captured) => { return captured(); });

        var stuffs = new Stuffs(cacheMock.Object);

        // Act

        var result = stuffs.GetModel();

        // Assert

        Assert.Equals(5, result.MyProperty);

    }

}

​

public class MyModel

{

    public int MyProperty { get; set; }

}

​

public class Stuffs

{

    private ICache _cache;

    public Stuffs(ICache cache)

    {

        _cache = cache;

    }

    public MyModel GetModel()

    {

        var model = _cache.GetOrSet("cache-key", () => 

                                    {

                                        return new MyModel

                                        {

                                            MyProperty = 5

                                        };

                                    });

        return model;

    }

}

​

public interface ICache

{

    T GetOrSet<T>(string key, Func<T> setter);

}

​

public class Cache : ICache

{

    public T GetOrSet<T>(string key, Func<T> setter)

    {

        // do stuff

        return setter();

    }

}