ArgumentException after upgrading from Moq 4.10.1 to 4.11 (and later)

I have a mock that is created, using Autofixture.Moq nuget package, with:

var fixture = new Fixture();
fixture.Customize(new AutoMoqCustomization());
var myMock = fixture.Create<IMyInterface>()

That was working with Moq 4.10.1 but no more with Moq 4.11 and later.

But now, when calling a method on this mock, I’ve got the exception:

System.ArgumentException
Argument types do not match
   at ConstantExpression System.Linq.Expressions.Expression.Constant(object value, Type type)
   at void Moq.Mock.AddInnerMockSetup(Invocation invocation, object returnValue)
   at void Moq.Return.Handle(Invocation invocation, Mock mock)
   at void Castle.DynamicProxy.AbstractInvocation.Proceed()
   at Dictionary<int, CategoryResult[]> Castle.Proxies.ICoreServiceProxy.GetCategoryResultsFormattedForEntity(out long cacheRevision, Nullable<int> idAnalysis, int entityID, List<AttributeAndFormat> attributes, int beginPeriod, int endPeriod, Periodicity periodicitySelected, bool ignoreOutOfBounds, TalianceToken talianceToken, Nullable<int> idSnapshot)

Could you give me a clue from where the problem could come from?

I’m not really sure if it’s a AutoFixture.Moq problem (and need an update with newer moq releases) or a Moq regression… So including @stakx in the report.

[pmiossec]

Giving another quick try to update from “4.10.1” to “4.16.0” and AutoFixture.AutoMoq from “4.11.0” to"4.15.0" and I still have the problem.

I have a better stacktrace:

System.ArgumentException
Argument types do not match
   at ConstantExpression System.Linq.Expressions.Expression.Constant(object value, Type type)
   at InvocationShape Moq.InvocationShape.CreateFrom(Invocation invocation) in C:/projects/moq4/src/Moq/InvocationShape.cs:line 31
   at void Moq.Behaviors.ReturnBaseOrDefaultValue.Execute(Invocation invocation) in C:/projects/moq4/src/Moq/Behaviors/ReturnBaseOrDefaultValue.cs:line 82
   at void Moq.Mock.Moq.IInterceptor.Intercept(Invocation invocation) in C:/projects/moq4/src/Moq/Interception/Mock.cs:line 34
   at void Moq.CastleProxyFactory+Interceptor.Intercept(IInvocation underlying) in C:/projects/moq4/src/Moq/ProxyFactories/CastleProxyFactory.cs:line 107
   at void Castle.DynamicProxy.AbstractInvocation.Proceed()

I don’t have a good understanding because that’s a big dirty test (not unit at all!!) but the behavior change is still there. I have to figure it out what is the real problem but that will require more investigation…

[aivascu]

@jzabroski I have reproduced the setup from the original post with the latest AutoFixture and I could not reproduce the failure. I used a .NET Framework unit test project with the following dependencies.

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="AutoFixture" version="4.14.0" targetFramework="net472" />
  <package id="AutoFixture.AutoMoq" version="4.14.0" targetFramework="net472" />
  <package id="Castle.Core" version="4.4.0" targetFramework="net472" />
  <package id="Fare" version="2.1.1" targetFramework="net472" />
  <package id="Moq" version="4.11.0" targetFramework="net472" />
  <package id="MSTest.TestAdapter" version="2.1.1" targetFramework="net472" />
  <package id="MSTest.TestFramework" version="2.1.1" targetFramework="net472" />
  <package id="System.Runtime.CompilerServices.Unsafe" version="4.5.0" targetFramework="net472" />
  <package id="System.Threading.Tasks.Extensions" version="4.5.1" targetFramework="net472" />
</packages>

The following test fails.

[TestMethod]
public void MockCreationShouldFail()
{
    var fixture = new Fixture();
    fixture.Customize(new AutoMoqCustomization());
    Action act = () => fixture.Create<IMyInterface>();

    Assert.ThrowsException<Exception>(act);
}

public interface IMyInterface
{
}

Closing this issue. If anyone finds a reproducible example, feel free to reopen the issue.