MSTest: "File extension specified '.dll' is not a valid test extension"

Question

I have a test project in VS2010, and I need to run the unit tests from command line. On one machine the following scenario works just fine:

1) Build the tests via "MSBuild test_project.csproj"

2) Run the tests via "MSTest /testcontainer:test_project.dll"

But on the other machine the 2nd step produced a weird error message, namely: "File extension specified '.dll' is not a valid test extension"

Any idea how to tackle this?

Thanks!

Answer 1

Check the registry on a PC that has Visual Studio 2010 installed: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\VisualStudio\10.0\EnterpriseTools\QualityTools\TestTypes\.

This contains all entries in regards to allowed extensions for MSTest. It would also probably be best to search for the test type keys (e.g. {13cdc9d9-ddb5-4fa4-a97d-d965ccfc6d4b}) and making sure they exist (.dll must be in the list of allowed extensions)

Answer 2

If your 'other machine' is the build machine and there's no Visual Studio installed, you need to install Test Agent and Test controller (http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=1334).

Take a look at the post Running tests in mstest without installing the VS IDE (http://blogs.msdn.com/b/anutthara/archive/2009/12/16/running-tests-in-mstest-without-installing-the-vs-ide.aspx)

Answer 3

If you are missing any of the following files it may cause this exception:

The files can be in the same directory or any configured directory. Configured locations can be found in MSTest.exe.config as an attribute on the probing element.