After creating some tests, I wanted to exclude some assemblies from the code coverage. In Visual Studio 2010 this could be done through the .testsettings file. In Visual Studio 2013you’ll notice that a .testsettings file is no longer included in a unit test project. The newer test framework, introduced in Visual Studio 2013, can be configured using a .runsettings file.
If you use a .testsettings file, the MSTest test framework will be used to run your tests. This runs more slowly and does not allow you to run tests from third-party test frameworks.
The stupid thing is that, although the .runsettings file is the recommended solution, Microsoft only added a .testsettings template to Visual Studio 2013. In the MSDN documentation they mention creating a custom XML file and renaming it, but there is a better solution.
In the Visual Studio Gallery, you can find a solution item template that creates a default runsettings file under Solution Items, and saves you from having to do this manually. See http://msdn.microsoft.com/en-us/library/vstudio/jj159530.aspx for information on how to change the default settings.
The runsettings file is used to change the code coverage analysis settings for a test run, in particular which files to be included and excluded from analysis, and also used to set symbol search paths.