How can I prevent a VerificationException when running a test with attached debugger?

Question

Whenever I run either of the following unit test with a debugger attached, I get a VerificationException inside FluentValidation code at this point (will post whole stacktrace later if necessary):

at FluentValidation.Resources.LocalizedStringSource.CreateFromExpression(Expression`1 expression, IResourceAccessorBuilder resourceProviderSelectionStrategy)
in ...\FluentValidation\Resources\LocalizedStringSource.cs:line 66

The tests are:

using FluentValidation;
using Microsoft.VisualStudio.TestTools.UnitTesting;

[TestClass]
public class UnitTest1
{
    [TestMethod]
    public void TestMethod1()
    {
        var c = new MyClass();
        var v = new MyValidator();
        v.Validate(c);
    }

    [TestMethod]
    public void TestMethod2()
    {
        Exception ex = null;
        var done = new ManualResetEvent(false);
        ThreadPool.QueueUserWorkItem(
            o =>
            {
                try
                {
                    TestMethod1();
                }
                catch (Exception e)
                {
                    ex = e;
                }
                finally
                {
                    done.Set();
                }
            });

        done.WaitOne();
        Assert.IsNull(ex);
    }
}

public class MyValidator : AbstractValidator<MyClass>
{
    public MyValidator()
    {
        RuleFor(c => c.MyProperty).GreaterThan(0);
    }
}

public class MyClass
{
    public int MyProperty { get; set; }
}

I've referenced just these assemblies in a single-solution, single-project scenario, targeting the 4.0.30319 runtime:

FluentValidation v3.0.0.0
Microsoft.VisualStudio.QualityTools.UnitTestFramework v10.0.0.0
System
System.Core

Some other points:

Running the test without a debugger works fine
Code coverage is turned off
I've minimized the referenced assemblies down to the minimum
I don't see any errors in the Fusion log
I tried applying the SecurityRulesAttribute from the answer to a similar question
I tried some things from a blog post on VerificationException and testing
Occurs under both MSTest and Resharper hosts (haven't tried NUnit, because the common thread seems to be 'under debugger'.
Occurs when running VS as admin or non-admin

Does anyone know how I can prevent this VerificationException, work around it, and/or why it's being caused? It seems with so few assemblies, there shouldn't be any conflicting ones loading. I've also moved the FluentValidation satellite assemblies out of the way but still get the exception.

score 12 · Accepted Answer · edited Jun 20 '20 at 09:12

12

Ok, I've got it. First I'd like to acknowledge Jeremy Skinner for working with me to reproduce the problem. His help spurred me to try tweaking my environment further.

To prevent the problem you either have to disable IntelliTrace in Visual Studio 2010 Ultimate, or you have to add FluentValidation to the list of modules that IntelliTrace should exclude from collecting data. My web searches seem to indicate it's an IntelliTrace bug. Jim Nakashima in his blog post says:

The issue is that IntelliTrace itself has a bug where methods that have a boolean out parameter in an assembly that is marked as SecurityTransparent will fail when IntelliTrace collection is set to “high” which is the default in the Cloud IntelliTrace scenario.

You will see this in your own code if you have a method whose signature includes a boolean out parameter and you have set your assembly security to SecurityTransparent.

I looked at my stack trace and briefly through the FluentValidation source, but didn't see this. I suspect it might be a similar IntelliTrace instrumentation bug relating to LINQ expressions.

Anyway, here's how to fix the issue:

In VS, select Debug | Options And Settings... | IntelliTrace | Modules
In the following dialog, click Add... and enter FluentValidation into the text box.

enter image description here

edited Jun 20 '20 at 09:12

Community

1
1

answered Jul 29 '11 at 14:58

Kit

20,354
4
60
103

I have a very similar problem, but the exception is thrown from Razor, and I have no IntelliTrace... I can run the tests at home, using VS Pro, but in the office, still using VS Pro, I get the exception. How did you manage to trace the cause to IntelliTrace? – Vegar Dec 22 '11 at 20:18
I didn't trace it directly to IntelliTrace, but inferred its code-instrumentation and Debug-mode was somehow causing this. Is anything in your technology stack instrumenting code (e.g. a memory/performance profiler, PostSharp, etc.?) It may be one of those... – Kit Jan 03 '12 at 21:19
1

TypeMock was the problem in this case. A version upgrade solved the case. It's a little bit scary that TypeMock interferes without my knowledge. I wonder what it does...? – Vegar Jan 04 '12 at 08:51
To be sure it's doing IL gen somewhere. Creating verifiable IL using, say reflection emit, is difficult -- I've often gotten InvalidProgramException in the past when I thought I was doing the right thing. – Kit Jan 04 '12 at 13:27
I am having the same issue, but this does not resolve it. Any suggestions? – Sam Aug 16 '12 at 21:08

score 1 · Answer 2 · edited Jan 09 '13 at 19:07

1

I experienced the same issue and found TypeMock 6.0 to be the culprit. By disabling TypeMock Isolator (menu TypeMock -> Disable TypeMock Isolator) I got rid of the problem. This of course breaks any TypeMock dependent test.

Note that adding FluentValidation to IntelliTrace exceptions does not resolve the issue when TypeMock is the problem.

edited Jan 09 '13 at 19:07

Kit

20,354
4
60
103

answered Dec 11 '12 at 10:20

larsmoa

12,604
8
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score 0 · Answer 3 · answered Dec 28 '13 at 15:44

In my case my Asp.net MVC 3 application had a reference to FluentValidation.dll and FluentValidation.mvc.dll files.

I removed the references and installed the FluentValidation for MVC 3 using nuget package manager and It worked.

It downloaded FluentValidation.Mvc version 5.0.0.1

How can I prevent a VerificationException when running a test with attached debugger?

3 Answers3

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