using System;

using System.Collections.Generic;

using System.Linq;

using Moq;

using Moq.AutoMock;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        Test();

    }

    public static void Run()

    {       

        var calc = new Calculadora(new ConsoleWrapper());

        Console.WriteLine("Multiplication: {0}",calc.Multiply());

    }

    public static void Test()

    {

        var mocker = new AutoMocker();

        var inputs = new []{"a","2","3"}.AsEnumerable().GetEnumerator();

        var outputs = new List<string>();

        {

            var wrapper = mocker.GetMock<IConsoleWrapper>();

            // mock ReadLine

            wrapper

                .Setup(x=>x.ReadLine())

                .Returns(

                    ()=>{

                        inputs.MoveNext();

                        Console.WriteLine("ReadLine[Injected]: {0}",inputs.Current);

                        return inputs.Current;

                    });     

            // mock WriteLine

            wrapper

                .Setup(x=>x.WriteLine(It.IsAny<string>()))

                .Callback<string>(

                    (str)=>{

                        outputs.Add(str);                       

                        Console.WriteLine("WriteLine[Intercepted]: {0}",str);

                    });

            mocker.Use(wrapper);

        }

        // create the calculator, injecting the mocked IConsoleWrapper automatically

        var calc = mocker.CreateInstance<Calculadora>();

        Console.WriteLine("Multiplication: {0}", calc.Multiply());      

    }

}

​

public class Calculadora

{

    private readonly IConsoleWrapper _console;

    public Calculadora(IConsoleWrapper console)

    {

        _console = console;

    }

    public double Multiply()

    {

        _console.WriteLine("Multiplying");

        double x,y;

        _console.WriteLine("X:");

        while(!Double.TryParse(_console.ReadLine(), out x))

        {

            _console.WriteLine("Invalid Input.");           

        }

        _console.WriteLine("Y:");

        while(!Double.TryParse(_console.ReadLine(), out y))

        {

            _console.WriteLine("Invalid Input.");           

        }

        return x*y;

    }

}

​

public interface IConsoleWrapper

{

    string ReadLine();

    void WriteLine(string s);

}

​

public class ConsoleWrapper : IConsoleWrapper

{

    public string ReadLine() => Console.ReadLine();

    public void WriteLine(string s) => Console.WriteLine(s);

}