using System;

​

public class MyUnitTest

{

    // CODE BEING TESTED

    class Product {

        public string Price() {

            return "I WANT TO STUB THIS OUT, DONT WANT TO SEE THIS STRING";

        }

    }

    class User {

        public string Foobar() {

            Product product = new Product();

            return $"Foobar, Product#price returns: {product.Price()}";

        }    

    }

    //////////////////////

    // CODE THAT DOES THE TEST

    public void Mock(string mockedClass, string mockedFunction, string mockedReturn)

    {

        // no idea what to put here something to do with an interface

        // or maybe create a string with csharp compiler, but then the generated class just goes into a obj variable, and so doesn't get called by the code being tested.

    }

    public void RunTests()

    {

        Mock("Product","Price","MOCKED DATA");

        string expected = new User().Foobar();

        Assert(expected, "Foobar, Product#price returns: MOCKED DATA");

    }

    public void Assert(string actual, string expected){

        Console.WriteLine(actual == expected);

    }

    //////////////////////

​

    // How do I stub out Product to return "MOCKED DATA"?

}

public class Program

{

    public static void Main(){

        new MyUnitTest().RunTests();

    }

}