using System;

using System.Collections.Generic;

using Moq;

using Newtonsoft.Json;

public class Program

{

    public static void Main()

    {

        string ValidJson1 = @"[

   {

      'CreatedBy':'test@test.org',

      'OrderNo':'Pizz111',

      'Amount':'10$',

   }

]";

        string ValidOutputJson1 = @"{

   'OrderNo': '808098',

    'Item': 'Pizza'

}";

        Mock<IMyInterface> myInterfaceMock =new Mock<IMyInterface>();

        var input = JsonConvert.DeserializeObject<List<Order>>(ValidJson1);

        myInterfaceMock.Setup(m=>m.myOrder(It.IsAny<List<Order>>())).Returns(ValidOutputJson1);

        // Act

        var myInterface = myInterfaceMock.Object;

        var result = myInterface.myOrder(JsonConvert.DeserializeObject<List<Order>>(ValidJson1));

        // Assert

       result.Dump();

    }

}

​

public interface IMyInterface

{

    public string myOrder(List<Order> order);       

}

​

public class Order

{

    public string OrderNo {get; set;}   

    public string CreatedBy {get; set;}   

    public string Amount {get; set;}   

    public string Item {get; set;}   

}