Moq - setup method with generic anonymous parameter

Question

I have a method with the following signature:

public string ParseFile<T>(string filepath, T model)

As you can see, the model is a generic type. The method is called from the tested code like this:

var model = new
        {
            SubmittedBy = submittedBy,
            SubmittedDateTime = DateTime.Now,
            Changes = changes
        };
string mailTemplate = provider.ParseFile(filePath, model);

I supply a mock object for the provider . I need to fake the call of this method, to return the value I provide, ie I need something like this:

_mockTemplateProvider.Setup(
            x => x.ParseFile(It.IsAny<string>(), It.IsAny<object>())).Returns("something");

When the test runs, the value I'm trying to set up is not returned. I can't use It.IsAny(), since the actual type is anonymous. If I try calling the method with an actual instance of object in debugger, it works. But how do I convince it to take an anonymous object? Or just don't care about arguments at all?

Answer 1

The anonymous type is still an object , and the setup method you posted should be matched. Here is a working example

public interface IThing
{
    string DoIt<T>(T it);
}

public class Subject
{
    ...

    public string Execute()
    {
        var param = new
        {
            Foo = "bar",
            Baz = 23
        };
        return _thing.DoIt(param);
    }
}

[Test]
public void Test()
{
    var mockThing = new Mock<IThing>();
    mockThing.Setup(t => t.DoIt(It.IsAny<object>()))
        .Returns("expectedResult");

    var subject = new Subject(mockThing.Object);
    var result = subject.Execute();

    Assert.That(result, Is.EqualTo("expectedResult"));
}

You can also capture the object that is passed into the mock and perform assertions on it using a dynamic + the Callback method.

[Test]
public void Test()
{
    dynamic param = null;

    var mockThing = new Mock<IThing>();
    mockThing.Setup(t => t.DoIt(It.IsAny<object>()))
        .Callback<object>(p => param = p);

    var subject = new Subject(mockThing.Object);
    subject.Execute();

    Assert.That(param.Foo, Is.EqualTo("bar"));
    Assert.That(param.Baz, Is.EqualTo(23));
}