Thursday, December 3, 2009

Watin 2.0 and Gallio 3.1 in x64 environment: fixing System.Reflection.ReflectionTypeLoadException and System.Runtime.InteropServices.COMException "The interface is unknown" issues

We use Gallio/MbUnit and Watin at my work for unit testing of an ASP.NET website, as it provides excellent reports including the raw Watin events (click, type, select) and screenshots for failed cases. Today I spent a few hours trying to get the project working on my new Windows 7 x64 development machine, and things did not start out very well. When I first tried to load the project in the Gallio Icarus runner none of the unit tests showed up and it indicated that an exception was thrown while exploring tests. I tried using both the x64 and x86 versions of Gallio/MbUnit, and even tried using the TestDriven.NET loader from within Visual Studio, but couldn’t get anything to work. Here is the full error message for Google’s sake:

[error] An exception was thrown while exploring tests.
Location: D:\SVN_Development\OQA Unit Testing\OQA Testing Framework\OQA Testing Framework\bin\Debug\OQA Testing Framework.EXE
Reference: OQA Testing Framework, Version=, Culture=neutral, PublicKeyToken=null
Details: System.Reflection.ReflectionTypeLoadException: Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information. 
   at System.Reflection.Module._GetTypesInternal(StackCrawlMark& stackMark) 
   at System.Reflection.Assembly.GetTypes() 
   at Gallio.Common.Reflection.Impl.NativeAssemblyWrapper.GetTypes() in c:\RelEng\Projects\MbUnit v3.1\Work\src\Gallio\Gallio\Common\Reflection\Impl\NativeAssemblyWrapper.cs:line 72 
   at Gallio.Framework.Pattern.TestAssemblyPatternAttribute.PopulateChildrenImmediately(IPatternScope assemblyScope, IAssemblyInfo assembly) in c:\RelEng\Projects\MbUnit v3.1\Work\src\Gallio\Gallio\Framework\Pattern\TestAssemblyPatternAttribute.cs:line 147 
   at Gallio.Framework.Pattern.TestAssemblyPatternAttribute.Consume(IPatternScope containingScope, ICodeElementInfo codeElement, Boolean skipChildren) in c:\RelEng\Projects\MbUnit v3.1\Work\src\Gallio\Gallio\Framework\Pattern\TestAssemblyPatternAttribute.cs:line 75 
   at Gallio.Framework.Pattern.DefaultPatternEvaluator.Consume(IPatternScope containingScope, ICodeElementInfo codeElement, Boolean skipChildren, IPattern defaultPrimaryPattern) in c:\RelEng\Projects\MbUnit v3.1\Work\src\Gallio\Gallio\Framework\Pattern\DefaultPatternEvaluator.cs:line 153

The error message indicates that it is due to an issue with missing assemblies, and suggested that you make sure the CopyLocal option is set to true for all 3rd party references, but that didn’t help either. Finally I created a test project and started ripping the original project to peaces to find out why it was failing. Turns out it worked fine if I remove a reference to an interface stored in the Watin.Core.Dll assembly, so I setup a workaround and was finally able to load the tests. Only problem was that it would fail whenever the test tried to load Watin. At this point I figured it had to be an issue with the Watin dll, and it turns out that it was simply trying to load an x64 version of the library that doesn’t actually exist (the library is x86 only). This link suggested setting Visual Studio to use x86 as the build platform type instead of “Any CPU”, and once I did that the original project started working. Yay!

It didn’t take long though for something else to fail, as it threw an exception as soon as one of the tests tried to access the Document object. This time the exception was System.Runtime.InteropServices.COMException with Message="The interface is unknown. (Exception from HRESULT: 0x800706B5)" coming from mshtml.HTMLDocumentClass.IHTMLDocument2_get_url(). Another quick search lead to another StackOverflow answer suggesting to run Visual Studio as an Administrator. That seem to do the trick!

So if you are using an x64 machine to do unit testing with Gallio, MbUnit, and Watin, make sure to set the platform to x86 and make sure to run Visual Studio and Icarus as an Administrator! I should probably get back to working on those unit tests now :-P


Blog.TheG2.Net - Your guide to life in the Internet age.