TDD with Sitecore 7 and TFS 2012 CI

Question

So, testing with Sitecore. It's a special topic and I've found allot of reading material regarding it already. (Sitecore Development Chapter 8, Alistair Deneys blog, NextDigital blog, iStern blog,...) but in most of these cases they're going with NUnit and custom test runners etc... The most useful (to me in my context) this far was the iStern blog for mocking out Sitecore using Microsoft Fakes. But is this really the way to go?

I'm surprised that with Hedgehog TDS system to integrate so deeply with TFS and be able to do CI in Sitecore development that there isn't more on how to utilize this system for setting up solid testing executed by TFS (yet).

We're gearing up for a large new project now that uses Sitecore to handle front-end user interaction where the data being used is 95% behind a WCF service. So this part can be easily tested and TDD developed. It's the last 5% (which sadly includes like the highest business value, being online payments) that resides within Sitecore that needs to be tested. Can we ever have enough intimate knowledge of sitecore to mock it out? I'd be inclined to think not... if so, how then do we run conclusive tests on our TFS CI build against sitecore?

Last but not least I get the feeling that the information currently to be found is getting a bit out of date perhaps (maily seeing the remarks on the NextDigital blog), does Sitecore 7 open new ways to tackle this issue?

For those who'd see this more as a philosophical rather then a technical question: There can only be one answer to this and that is a technical accurate definition of a method of using the Microsoft test framework that is capable of running in the TFS CI environment to test code written for Sitecore.

Answer 1

I was in the exact same situation as you, IvanL, a few weeks ago. I wanted to test some of my business logic running against Sitecore 7 without a mocking framework. I managed to do it, but only in a very specific scenario. Unfortunately, I haven't published my prototype solution or the slides explaining it yet, but I'll explain the basics of what I did.

In Sitecore 7, the move towards querying against the index with the Sitecore.ContentSearch namespace and using LINQ opened up a way for me to very easily unit test with fake index data.

There are some unit test examples out there, as you've seen, that use mocking frameworks. However, the classes they mock are actually quite simple to fake out yourself. If you implement ISearchIndex, you really only need to implement the CreateSearchContext method in order to start returning an IQueryable to work with in your tests.

To implement CreateSearchContext, you will likely need to create a fake provider search context implementation that will do the GetQueryable implementation.

Once you have those two classes set up, you've essentially got your 'index' covered. Add a property onto it where you can set the data collection from the unit test and then make sure the context returns that data collection.

That will let you build up a fake index with whatever data POCOs you want, and then pass that through to your standard provider implementations that are running your business data.

The big thing to remember is that this only works for any code you may be writing that will use the new Sitecore 7 way of using LINQ and the IQueryable implementation. Older style code that is running using the Sitecore.Data.Item API still works the way it used to, and has the same limitations as before.

Update: The prototype I mentioned is now available for download: http://blog.nonlinearcreations.com/2014/02/sitecore-7-developers-quest-successful-unit-testing/

Answer 2

Is Microsoft Fakes the way to go? In my opinion, no. Microsoft fakes allows you to test code that is not designed to be testable. If you design you solution properly, a standard mocking framework should be sufficient.

Can we ever have enough intimate knowledge of sitecore to mock it out? This is kind of a trick question. Unless a third-party library was specifically designed for it and is something that you would consider a "stable dependency", you shouldn't try to mock it. Instead, wrap it with your own classes and abstractions and mock those.

Take a look at Synthesis and Glass Mapper. They are object-mapping frameworks that allow you to map Sitecore items to interfaces while maintaining page editor support. Glass, in particular has a wrapper around Sitecore.Context that can be mocked. Synthesis is supposed to be pretty testable as well, but I haven't tried it yet.

Using one of those mapping frameworks and a good SOLID design, you should be able to make most of your code testable. Just remember that the classes on the edges of your solution should be simple enough to not require testing.