How to programmatically start a WPF application from a unit test?

MyProject.App myApp = new MyProject.App();myApp.InitializeComponent();myApp.Run();

I am doing something similar in VS2008 and manually creating the tests using UI Spy to help me identify the controls and some helper methods, not shown, to trigger button clicks and verify values on the screen. I use the Process object to launch the application I am testing in the TestInitialize method and in the TestCleanup method I close the process. I have a number of ways to ensure the process has completely closed in the CleanUp. As for the absolute path problem, I just programmatically lookup the current path and append my application's executable. Since I don't know how long it takes for the application to start I put an AutomationId in my main window and set it to "UserApplicationWindow" and wait for that to be visible, of course, you may have something else you could wait for. Finally, I use the MyTestClass as a base class and extend the class for different tests.

[TestClass]public class MyTestClass{    private Process _userAppProcess;    private AutomationElement _userApplicationElement ;    /// <summary>    /// Gets the current directory where the executables are located.      /// </summary>    /// <returns>The current directory of the executables.</returns>    private static String GetCurrentDirectory()    {        return Path.GetDirectoryName(new Uri(Assembly.GetExecutingAssembly().GetName().CodeBase).AbsolutePath).Replace("%20", " ");    }    [TestInitialize]    public void SetUp()    {        Thread appThread = new Thread(delegate()        {            _userAppProcess = new Process();            _userAppProcess.StartInfo.FileName =GetCurrentDirectory() + "\\UserApplication.exe";            _userAppProcess.StartInfo.WorkingDirectory = DirectoryUtils.GetCurrentDirectory();            _userAppProcess.StartInfo.UseShellExecute = false;            _userAppProcess.Start();        });        appThread.SetApartmentState(ApartmentState.STA);        appThread.Start();        WaitForApplication();    }    private void WaitForApplication()    {        AutomationElement aeDesktop = AutomationElement.RootElement;        if (aeDesktop == null)        {            throw new Exception("Unable to get Desktop");        }        _userApplicationElement = null;        do        {            _userApplicationElement = aeDesktop.FindFirst(TreeScope.Children,                new PropertyCondition(AutomationElement.AutomationIdProperty, "UserApplicationWindow"));            Thread.Sleep(200);        } while ( (_userApplicationElement == null || _userApplicationElement.Current.IsOffscreen) );    }    [TestCleanup]    public void CleanUp()    {        try        {            // Tell the application's main window to close.            WindowPattern window = _userApplicationElement.GetCurrentPattern(WindowPattern.Pattern) as WindowPattern ;            window.Close();            if (!_userAppProcess.WaitForExit(3000))            {                // We waited 3 seconds for the User Application to close on its own.                  // Send a close request again through the process class.                _userAppProcess.CloseMainWindow();            }            // All done trying to close the window, terminate the process            _userAppProcess.Close();            _userAppProcess = null;         }        catch (Exception ex)        {            // I know this is bad, but catching the world is better than letting it fail.        }    }}

I ended up using ApplicationUnderTest.Launch(...) (MSDN) which is automatically created when recording an automated test with Microsoft Test Manager.