Why Typemock Isolator does not work on TFS 2012 Build and what you can do about it

Update 4/Aug/2012: See post on my implementation of a 2012 version of this activity

If you are using Typemock Isolator in your unit testing then you be wanting to include then in your automated build process. Unlike other mocking frameworks you have to do a bit of work to achieve this with Isolator, this is because to enable its advanced features of mocking items like sealed private classes you have to start the interceptor that does the magic prior to running the tests and the switch it off afterwards.

In the past [I posted on how you could use a build activity I wrote to wrapper MStest in a TFS 2010 build using TMockRunner](http://tfsbuildextensions.codeplex.com/wikipage?title=TFS Build 2010 Activity to run Typemock Isolator based tests&referringTitle=Home&ProjectName=tfsbuildextensions). Since I wrote this Typemock released a set of build activities to do the starting and stopping of the inceptor as separate activities, a much more flexible solution which I would always recommend for TFS.

However when you try to use either with TFS 2012 you get a problem, the activities fail to load. This is a problem we saw on the TFS Extensions Codeplex project; you have to build you activities against either the 2010 TFS API or the 2012 TFS API. You don’t need to alter the code in your activities, but you do need to make a specific build.

So at this time there is no solution, one or both of these activities need to be rebuilt. For the MSTest wrapper I wrote the [source is available](http://tfsbuildextensions.codeplex.com/wikipage?title=TFS Build 2010 Activity to run Typemock Isolator based tests&referringTitle=Home&ProjectName=tfsbuildextensions) so you can do it yourself if you want to, but the way Typemock have implemented their activities is a better solution. This is because it is not reliant on TMockRunner and MStest, it can wrapper any activities. This is important as to be able to use the new ‘any framework’ unit testing features in VS2012 you want to use Microsoft’s new test running activities and not just the old MSTest activity.

I understand that Typemock are looking at releasing a TFS2010 version of their activities soon, but I know of no release date as yet. If you want an immediate solution you will need to do a bit of work.

• You could rebuild my MSTest based activity
• You could use the standard InvokeMethod activity and put the contents of my MStest activity’s generated command line into this
• But the one I favour is to use a dissembler such as Telerik JustDecompile to get the code from the Typemock.TFS2010.DLL and build a new activity.

However, it must be said I see this as just a temporary measure until the official Typemock 2012 activity is released. I am not sure I will get around to doing this before the Typemock release, we shall see.