If you are using VS 2010 Premium or Ultimate, you can get the code coverage from VS itself (You can find more posts related to code coverage here.). But if you are using Professional or less, you won’t get this code coverage feature. From last few months I am using VS Pro edition, and some time breaking the CI build because of low code coverage of my class. Today I found an alternative, PartCover 4.0 which helps to measure code coverage. You can download PartCover 4.0 . Installation is pretty easy, like any other software, and it has two parts UI version and command line version. I this post I am talking about UI version, which is called Part Cover browser.

1. Open the Part cover browser, it will be displayed like this.
   
   

   Part Cover Browser

2. Select File menu and click on the Run Target menu. It will popup a Window like this.
   
   

   Run target settings

   
   In the window,
   1. Executable File : It the application required to run unit tests, in this case it MSTest.exe, normally which will be available in C:\Program Files\Microsoft Visual Studio 10.0\Common7\IDE\ location.
   2. Working Directory : After choosing the Executable file, Part cover automatically fill this location, by the same location of Executable, but you may need to change it and select the location, where your assemblies created.
   3. Working Arguments : This entry is required if you want to pass any parameters to the unit test engine as command line argument. For MS Test, it will be “/noisolation /testcontainer:YOUR UNIT TEST ASSEMBLY.” If you are using NUnit it will bedifferent.
   4. Rules : And the next and most important thing is Rules, which helps Part cover to give you coverage metrics for the specified assembly. If you want to get coverage of a assembly by including it and you can remove coverage by excluding it, it can be done using + and – signs respectively. Here is an example. Ignore namespaces, start with Microsoft.TeamFoundation and Microsoft.VisualStudio – -[Microsoft.TeamFoundation.*]* or -[Microsoft.VisualStudio.*]*
      And to include namespaces start with MySampleApp. +[MySampleApp.*]*. Or you cover all using +[*].
   5. Now click on the Start button, you can see two command line windows running and after few seconds it will display code coverage in the left side Treeview like this. Goto the View menu and select View coverage details, it will display the source code, with code coverage information, like this.
      

      Part cover with Code coverage results

You can save the configuration, for future purposes and load it before starting code coverage. Here is the code and test class files.

Source code

public class UserRepository
{
    private Dictionary<string, string> _users = new Dictionary<string,string>();

    public void AddUser(string name, string address)
    {
        if (_users.ContainsKey(name))
        {
            throw new Exception("User already exists");
        }
        _users.Add(name, address);
    }

    public string GetAddress(string name)
    {
        if (!_users.ContainsKey(name))
        {
            throw new Exception("User not exists");
        }
        return _users[name];
    }
}

And here is the unit test

[TestClass]
public class UserRepositoryTest
{
    private UserRepository _testObject;

    [TestInitialize]
    public void Setup()
    {
        _testObject = new UserRepository();
    }

    [TestMethod]
    public void TestAddUser()
    {
        string expectedUser = "anuraj";
        string expectedAddress = "anuraj's address";
        _testObject.AddUser(expectedUser, expectedAddress);

        string actualAddress = _testObject.GetAddress(expectedUser);
        Assert.AreEqual(expectedAddress, actualAddress);
    }

    [TestMethod]
    [ExpectedException(typeof(Exception))]
    public void TestAddUserWithExistingUsername()
    {
        string expectedUser = "anuraj";
        string expectedAddress = "anuraj's address";
        _testObject.AddUser(expectedUser, expectedAddress);

        _testObject.AddUser(expectedUser, expectedAddress);
    }
}

Happy coding.