How to setup Moq with Callbacks? - callback

Question

Ok, I have started to look at Moq, so this is a noob question.
I have followed the quick guide, and I am trying to setup a callback to return a specific model:
void Main()
{
var resultData = new MyModel();
var mock = new Mock<IMyClass>();
mock.Setup(x => x.Register(It.IsAny<string>()))
.Returns(new MyModel { Name = "Test" })
.Callback<MyModel>((data) =>
{
resultData = data;
});
var parameter = "123";
var result = mock.Object.Register(parameter);
}
public interface IMyClass
{
MyModel Register(string code);
}
public class MyModel
{
public string Name { get; set; }
}
I get this exception on the call:
ArgumentException: Object of type 'System.String' cannot be converted
to type 'UserQuery+MyModel'.
What am I doing wrong?

Answer 1

The T in the Callback<T> method should match the parameter type of the method being Setup. In other words, Moq is letting you set a callback method with the same parameters as the method being mocked.
I'm not exactly sure what you're trying to do here. If you're just trying to save the return MyModel object from your mocked method, do this:
var returnedModel = new MyModel { Name = "Test" };
mock.Setup(x => x.Register(It.IsAny<string>()))
.Returns(returnedModel);
If you're trying to create a MyModel with the given string parameter, do this:
mock.Setup(x => x.Register(It.IsAny<string>()))
.Returns((string data) => new MyModel { Name = data });