Tests Disappeared in Visual Studio 2013

Question

All of my unit tests have disappeared suddenly in Visual Studio 2013 and I can not seem to get them to be discovered in the Test Explorer.

We use visual studio 2010 as our primary environment. I have Visual Studio 2013 Express Desktop installed as my editor of choice, work in it, then do final build/check-in with 2010. Everything works fine in 2010. But 2013 express will not discover tests anymore. It used to, then in the middle of working a change it stopped. These are mstest tests.

I get the following Tests output:

------ Discover test started ------
TestTypes\13cdc9d9-ddb5-4fa4-a97d-d965ccfc6d4b could not be loaded because the TIP could not be instantiated for the following reason(s): System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.VisualStudio.QualityTools.Tips.UnitTest.Tip, Version=12.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The system cannot find the file specified.
File name: 'Microsoft.VisualStudio.QualityTools.Tips.UnitTest.Tip, Version=12.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'
   at System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMarkHandle stackMark, IntPtr pPrivHostBinder, Boolean loadTypeFromPartialName, ObjectHandleOnStack type)
   at System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean loadTypeFromPartialName)
   at System.RuntimeType.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark)
   at System.Type.GetType(String typeName, Boolean throwOnError)
   at Microsoft.VisualStudio.TestTools.TestManagement.TipDelayLoader.LoadTip()

WRN: Assembly binding logging is turned OFF.
To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1.
Note: There is some performance penalty associated with assembly bind failure logging.
To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].

========== Discover test finished: 0 found (0:00:00.1640164) ==========

Steps attempted to fix:

• Checked out fresh copy of source from the repository
• Verify other developers do not have this problem (their 2013 installs find tests)
• Repair 2013
• Remove 2013, reboot, install 2013
• Created new WPF project and added test (that test discovered, but problem not solved)

Any suggestions would be appreciated. My next step is to wipe the system, but that will be painful.

Answer 1

Are you using nUnit? I've just had a similar situation moving to a new pc, causing all existing tests to disappear.

Go to Tools -> Extensions and updates -> Select Online on the left -> enter in the search box top right 'nunit test adapter' and install it.

Restart Visual Studio.

One rebuild later and the tests appeared again.