Parameter Array modifier lost in mock

[afscrome]

The only way to detect through reflection if a method parameter is a parameter array is by checking if the parameter has the ParamArrayAttribute attribute defined on it. However when you mock a method with a params array, the mock implementation looses this attribute.

This behavior can be shown by the below test - I'd expect the last assertion to pass, but it currently fails.

public abstract class Base
{
    public abstract string ParamsArray(params int[] args);
}

[Test]
public void ParamsArrayLostOnMock()
{
    var baseMethodParam = typeof(Base).GetMethods()[0].GetParameters()[0];

    var mock = new Mock<Base>();
    mock.Setup(x => x.ParamsArray(1, 2, 3)).Returns("foo");

    var mockMethodParam = mock.Object.GetType().GetMethods()[0].GetParameters()[0];

    Assert.IsTrue(baseMethodParam.IsDefined(typeof(ParamArrayAttribute), false), "ParamArrayAttribute is not defined on base");
    Assert.IsTrue(mockMethodParam.IsDefined(typeof(ParamArrayAttribute), false), "ParamArrayAttribute is not defined on mock");
}

[kzu]

This is an issue in Castle.DynamicProxy most likely. Can you see if it can be reproduced with any of the other open source mocking libraries? (I.e. Rhino, NSubstitute, FakeItEasy, etc.?)

[afscrome]

I was able to reproduce with NSubstitue, as well as using ProxyGenerator directly - see castleproject/Core#121 .

[kzu]

Marking as an enhacement that has to happen in Castle.

[stakx]

A fix for this is going to be in Castle Core v4.1 (see castleproject/Core#121 (comment)). As soon as we upgrade Castle and republish Moq, this can be closed.