mstest.exe execution via command line with *.vsmdi - visual-studio-2010

Question

I have a visual studio solution of C# projects. Currently, I do not have test projects in my solution. So I do not have file *.vsmdi.
I want to test my projects via command line like this.
MSTest.exe /testmetadata:*.vsmdi /resultsfile:Logfile.log
Is it possible to create .vsmdi without adding project? if possible, how?
To execute in command line, *.vsmdi file MUST be present in the solution?
If I have to test using IDE, the I should have *.vsmdi file in test project?
The only use of *.vsmdi file is for listing the test cases?

Answer 1

1) Technically it’s possible to create a .vsmdi file without adding your test project(s) to your solution. Since the content of the VSMDI files is XML you can write them by hand or generate them with a tool based on the tests in your assembly. However, VSMDI files are less useful when the test projects are not included in the solution because the power of the VSMDI files is managing your tests. But you can still use them (see also answer to question 2).
If you want to write the vsmdi file by hand you need to hash the FQN with SHA1 and create a Guid of the first 128 bits of the hash as shown below (code from Dominic Hopton). See for more information his blog post: Helpful Internals of TRX (and VSMDI files).
private static HashAlgorithm s_provider = new SHA1CryptoServiceProvider();
internal static HashAlgorithm Provider
{
get { return s_provider; }
}
/// Calculates a hash of the string and copies the first 128 bits of the hash
/// to a new Guid.
///
internal static Guid GuidFromString(string data)
{
byte[] hash = Provider.ComputeHash(
System.Text.Encoding.Unicode.GetBytes(data));
byte[] toGuid = new byte[16];
Array.Copy(hash, toGuid, 16);
return new Guid(toGuid);
}
2) No, the vsmdi file doesn’t need to be in your solution folder (or in your solution) as long as the storage attribute of the TestLink element points to the correct assembly containing the test (relative to your vsmdi file). For example:
<TestLink id="0c257cc9-ffed-cd5e-bda1-56df14ad68c2" name="AddOneAndTwo_Test"
storage="TestProject\bin\debug\testproject.dll" />
3) Vsmdi files exists on the solution level and not at project level. If you have more than one test projects you can use one vsmdi file to manage all your tests. Please note that the storage attribute is ignored when you run the tests from Visual Studio assuming that you loaded the projects in your solution
4) Vsmdi files are used for managing the tests in your solution and you can create a hierarchy of several layers within the VSMDI file. For example you have more than one assembly in your solution you want to test. Under the root test list (called: List Of Tests) you create a test list for each of your projects. You can then divide the test list for one of the projects into two or more separate test lists (e.g. one for testing the business logic and one for testing the error handling). When you only want to test the business logic tests from project A you can select the corresponding test list and run the tests in it.
An extra note about vsmdi files:
A) Since Visual Studio 2012 Microsoft decided to make VSMDI files (and with them the test lists) deprecated. Test lists got replaced by Test Categories (already exists in Visual Studio 2010) and Playlists.
Test categories are attributes you can set on individual test methods and can be used in builds. Playlists were introduced in Visual Studio 2012 Update 2 and are currently not supported in MSBuild.
For more information about Test Categories see: http://msdn.microsoft.com/en-us/library/dd286595.aspx