Wednesday, October 17, 2012

[Tutorial] Test Driven Development with Visual Studio 2012
Part2: New features in Visual Studio 2012 (1/2)

The last blog post in the series introduced Test Driven Development (TDD). This blog post is going to talk about some of the new features in Visual Studio 2012, that allow you to successfully apply the TDD approach in your daily work.

Visual Studio 2012 external test framework support

The previous version Visual Studio 2010 already provides the possibility of using external test frameworks. But unfortunately with multiple limitations such as:

  • Dependency on third party applications for being able to execute unit tests. For example Gallio needs Icarus Runner if you want to run your unit tests.
  • Code coverage analysis does not work natively, only by using third party products (such as NCover for example).
  • Execution of unit tests is specific to certain plugins : for example there is a difference if you run your MSTest unit tests from within Visual Studio 2008 or by using Resharper, which may result in problems when trying to apply continuous integration processes.

As you can see, you have to multiply plugins and tools, that might not always be compatible with each other, when using Visual Studio 2010 with external test frameworks. Really not an optimal situation, when you want to benefit from specialized external test frameworks and their advanced functionalities !

One of the major updates of Visual Studio 2012 is the support of several external unit test frameworks for multiple languages without any of the limitations mentioned above.

Here are some of the unit test frameworks that you can now use easily:

For .NET :

For Javascript/HTML :

For C++ :

How to use NUnit as external test unit framework 

Lets see how to use NUnit as external test unit framework. First you have to install NUnit (currently as Prerelease) via NuGet.


Then you have to install the test adapter plugin for NUnit (currently as Beta) via the Extension Manager, which you can now find under “Tools/Extensions and Updates…”. Note that all test adapters are free of charge and that the functionality to search and download those adapters is fully integrated in Visual Studio 2012.



After installing the NUnit test adapter plugin, you are able to use all Visual Studio 2012 unit test functionalities together with NUnit. You may for example execute your NUnit unit tests directly from within the Visual Studio 2012 IDE, display the test results in the standard view “Test Explorer” and run a code coverage analysis on your code.


Support for C++ in native MSTest

Another big feature of Visual Studio 2012 is that it now supports native MSTest unit tests for C++ applications. Good news for C++ developers, who may now also apply Test Driven Development using native MSTest as unit test framework.


Following is an example implementation of a unit test in Visual C++ using the native MSTest unit test framework:


Support for async and await in VS 2012 and its unit test framework

Windows 8 and .NET 4.5 introduce a major feature that will have a high impact on software development as we know it: Asynchronous Programming. Visual Studio 2012 and its unit test framework support this new approach perfectly. The async and await keywords, available in .NET 4.5, may now be used for creating unit tests of asynchronous methods.

Lets say that you want to create a unit test for the following asynchronous example method:

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The corresponding NUnit test method could be:

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In my next blog post I am going to further show you other new features of Visual Studio 2012, which will make your life easier when trying to apply Test Driven Development.


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