I have posted in the past about getting Typemock Isolator to function within the TFS build process. In TFS 2008 it was easy, you just ran a couple of MSBUILD tasks that started/stopped the Typemock Isolator inception process (the bit that does the magic other mocking frameworks cannot do). However with TFS 2010’s move to a windows workflow based build model it became more difficult. This was due to the parallel processing nature of the 2010 build process, running a single task to enable interception cannot be guaranteed to occur in the correct thread (or maybe even on the correct build agent). So I wrote wrapper build activity for MStest to get around this problem. Howerver, with the release of Typemock Isolator 6.2 direct support for TFS 2010 was added and these TFS build activities have been refined in later releases. In the current beta (7.0.8) you get a pre-created TFS build process template to get you going and some great auto deploy features, but more of that later.
The problem was I wanted to put Isolator based tests within a TFS 2012 build process. I posted before about my initial thoughts on the problem. The main problem is that TFS build activities have to be built against the correct version of the TFS API assemblies (this is the reason the community custom activities have two sets of DLLs in the release ZIP file). So out the box you can’t use the Typemock.TFS2010.DLL with TFS 2012 as it is built against the 2010 API.
Also you cannot just use the Typemock provided sample build process template. This is built against 2010 too, so full of 2010 activities which all fail.
What I tried that did not work (so don’t waste your time)
So I took a copy of the default TFS 2012 build process template and followed the process to add the Typemock.TFS2010.DLL containing the Typemock activities to the Visual Studio 2012 toolbox (the community activity documentation provides a good overview of this strangely complex process also see the ALM Rangers guidance). I then added the TypemockRegister and TypemockStart activities at the start of the testing block. For initial tests I did not both adding the TypemockStop activity
I then made sure that
- Typemock was installed on the build agent PC
- The Typemock.TFS2010.dll was in the correct CustomActivities folder in source control
- The build controller was set to load activities from the CustomActivities folder.
However, when I tried to queue this build I got an error
Exception Message: Object reference not set to an instance of an object. (type NullReferenceException)
Exception Stack Trace: at TypeMock.CLI.Common.TypeMockRegisterInfo.Execute()
The issue was that though Typemock was installed, the required DLLs could not be found. Checking in a bit more detailed (by running the build with diagnostic level of logging and using Fuslogvw) I saw it was trying load the wrong versions of DLLs as expected. So the first thing I tried to use was binding redirection (a technique I used before with similar Typemock). This in effect told the Typemock activity to use the 2012 DLLs when it asks for the 2010 ones. This is done by using an XML config file (Typemock.TFS2010.DLL.config) in the same folder as the DLL file.
I first tried to add this file to the CustomActivities source control folder, where the custom activities are loaded from by the build agent, but that did not work. I could only get it to work if I put both the DLL and the config files in the C:\Program Files\Microsoft team Foundation Server 1.0\Tools folder on the build agent. This is not a way I like to work, too messy having to fiddle with the build agent file system.
Once this setting was made I tried a build again and got the build process to load, but the TypemockRegister activity failed as the Typemock settings argument was not set. Strangely Typemock have chosen to pass in their parameters as a complex type (of the type TypemockSettings) as opposed to four strings. Also you would expect this argument to be passed directly into their custom activities by getting activity properties to argument values, but this is not how it is done. The Typemock activities know to look directly for an argument called Typemock. This does make adding the activities easier, but not obvious if you are not expecting it. So I added this argument to the build definition in Visual Studio 2012 and checked it in, but when I tried to set the argument value for a specific build it gave the error that the DLL containing the type Typemock.TFS2010.TypemockSettings could not be loaded, again the TFS 2010/2012 API issue, this time within Visual Studio 2012
At this point I gave up on binding redirection, I had wasted a lot more time than this post makes it sound. So I removed all the work I had previously done and thought again.
What did work
I decided that the only sensible option was to recreate the functionality of the Typemock activity against the 2012 API. So I used Telerik JustDecompile to open up the Typemock.Tfs2010.dll assembly and had a look inside. In Visual Studio 2012 I then created a new C# class library project called Typemock.BM.TFS20102 targeting .NET 4. I then basically cut and pasted the classes read from JustDecompile into classes of the same name in the new project. I then added references to the TFS 2012 API assemblies and any other assemblies needed and compiled the project. The one class I had problems with the TypemockStart, specifically the unpacking of the properties in the InternalExecute method. The reflected code by JustDecompile was full of what looked to be duplicated array copying which did not compile. So I simplified this to map the properties to the right names.
You can download a copy of my Typemock.BM.TFS2012.Dll from here, so you don’t have to go through the process yourself.
I now had a TFS 2012 custom build activity. I took this new activity and put it the CustomActivities folder. Next I took an unedited version of the default 2012 build process template and added these new Typemockregister, TypemockStart (at the start of the test block) and TypemockStop (at the end of the test block) activities as well as a Typemock argument (of TypemockSettings type). I checked this new template into TFS, and then created a build setting the Typemock argument settings.
Now at this point it is worth mentioning the nice feature of AutoDeploy. This allows you to use Typemock without having it installed on the build agent, thus making build agent management easier. You copy the AutoDeploy folder from the Typemock installation folder into source control (though a rename might be sensible so you remember it is for Typemock auto deployment and not anything else). You can then set the four argument properties
- The location of the auto deployment folder in source control
- A switch to enable auto deployment
- Your Typemock license settings.
By using the auto deployment feature I was able to uninstall Typemock on the build agent.
So I tried a build using these setting, all the build activities loaded Ok and the TypemockSettings was read, but my project compile failed. As I had uninstalled Typemock on my build agent all the references to Typemock assemblies in the GAC failed. These references were fine on a development PC which had Typemock installed not on the build agent which did not.
So I needed to point the references in my project to another location. Typemock have thought of this too and provide a tools to remap the references that you can find on the Typemock menu
You can use this tool, or do it manually.
You could re-point the references to the same location you used for the AutoDeploy feature. However I prefer to keep my project references separate to my infrastructure (build activities etc.) as I use the same build templates cross project. For our projects we arrange source control so we have the structure in the general form (ignoring branch for simplicity)
A team project
I make sure we put all assemblies referenced in the lib folder, including those from Nuget using a nuget.config file in the src folder with the SLN file e.g.
This structure might not be to your taste, but I like it as it means all projects are independent, and so is the build process. The downside is you have to manage the references for the projects and build separately, but I see this as good practice. You probably don’t share want to reference and Nuget packages between separate projects/solutions.
So now we have a 2012 build process that can start Typemock Isolator, and a sample project that contains Typemock based tests, some using MSTest and some using XUnit (remember Visual Studio 2012 support multiple unit testing frameworks not just MSTest, see here on how to set this up for TFS build). When the build is run I can see all my unit tests pass to Typemock isolator must be starting correctly
So for me this is a reasonable work around until Typemock ship a TFS 2012 specific version. Hope this file saves you some time if you use Typemock and TFS 2012.