Often times, when a developer builds a C# library, there is always a need for unit testing it. If your company already has strictly guidelines on how to enforce unit testing before any code is checked in, you might want to read the policy procedure about how to do it. Visual Studio Team System 2008 can be configured to enforce such policy that if any unit tests fail, the check in is rejected. You can right click on the solution->New->Add project->Test->Test project to create unit tests. Every time, you change the data in your test, you need to re-compile the test dll and run the test. Don’t you think that’s an overhead for changing calls from ”client.CreateEmail("XBOX", "hil1@msn.com");” to “client.CreateEmail("Live", "hil1@msn.com");”? PowerShell comes handy to solve this problem. You can easily code unit tests for your methods and change them without re-compiling. Here is how:

1.       Install Windows PoweShell

2.       Open a PowerShell window, type powershell and hit enter. Notice there are 2 powershell.exe processes running. One is the parent and the other is the child. You are in the child process. Use process explorer to observe the 2 processes and write down the child process ID.

3.       Build the .NET library solution. The .dll should reside in bin\Debug folder.

4.       At powershell prompt, run PS > $loadResult = [Reflection.Assembly]::LoadFrom("D:\product\src\test\DataAccess\bin\Debug\Microsoft.IT.Product.Library.dll"). All the dll files referenced by Microsoft.IT.Product.Library.dll will also be loaded. Be aware that if you use [Reflection.Assembly]::LoadFile, the referenced dll files will NOT be loaded.

5.       If you see no errors and $loadResult shows no errors, you are probably fine.

6.       Command to instantiate your class: PS > $verify = New-Object Microsoft.IT.Product.Library.VerifyData("Data Source=.;Initial Catalog=EmailStore;Integrated Security=True"). Notice that VerifyData is the class name which takes a constructor of 1 string argument.

7.       Run a unit test on a method: PS > $verify.EmailExists("testuser@msn.com"). If the constructor throws an exception, you will see the following:
New-Object : Exception calling ".ctor" with "1" argument(s): "Database EmailStore does not exist"

At line:1 char:21

+ $verify = New-Object  <<<< Microsoft.IT.Product.Library.VerifyData("Data Source=.;Initial Catalog=EmailStore;Integrated Security=True")

8.       In Visual Studio 2008, click on Debug->Attach to Process… You should be able to see 2 PowerShell processes. Choose the child process. Remember you call [Reflection.Assembly]::LoadFrom in the child powershell process.

9.       After successfully attached to the correct process, you should be able to set break points at anywhere within your library. If the break point says “No symbols have been loaded for this document”, you probably have attached to the wrong powershell process.

10.   You can use PowerShell to run all the methods in your library to unit test them in Visual Studio. When you are done testing, unfortunately, you can’t unload the assembly. You need to exit the Child PowerShell to unload the assembly. Otherwise, you will get error when building the solution: Unable to delete file. That is because the child PowerShell process is still holding the loaded assembly. Simply type exit at the child PowerShell prompt to unload it.

11.   To test static method in the library, use [Microsoft.IT.Product.Library.VerifyData]::RandomString(4). RandomString is a static method that takes 1 int argument.

I mentioned developing an ASP.NET website in the first blog. ASP.NET is a sophisticated architecture that often confuses developers, especially which event fires first could be difficult to expect. You should understand ASP.NET Page Life Cycle before you start dragging WebControl to the page.

Task 1: Impersonation

Often times, you need to impersonate as a specific active directory user to connect to a server, check service status, or access MSMQ. Microsoft Support has a very good example page about how to impersonate as a specific user. You can change the impersonate method and undo impersonation method to be public static to allow all other methods in your application to use them. Below is the code showing how to consume the impersonation methods:

ServiceStatus.impersonated = ServiceStatus.impersonateValidUser("ServiceAccountUser","Domain","Don’tTell");

if (!ServiceStatus.impersonated)

{

    // impersonation failed. Do not continue to call Administration web service

string message = DateTime.Now + " - Impersonaion failed.”

Trace.WriteLineIf(ServiceStatus.debugSwitch.TraceError, message);

    throw new Exception(message);

}

Task 2: Start application thread

The static constructor is the best place you can start and manage a thread. The thread will exist in the scale of the application regardless of how many page instances there are at any moment. It is a useful practice if you need to run long haul SQL queries or you need to check Windows Service status every 10 minutes alongside your ASP.NET application.
// There should always be 1 static instance of ServiceStatus executing

// method ServiceStatus.StartChecking in the application pool

static _Default()

{

    if (_Default.logEnvStatus == null || !_Default.logEnvStatus.IsAlive)

    {

        _Default.logEnvStatus = new Thread(new ThreadStart(ServiceStatus.StartChecking));

        _Default.logEnvStatus.Start();

    }

    _Default.refreshTime = ServiceStatus.appSettings["RefreshTime"];

    _Default.MaxLatencyAllowed = int.Parse(ServiceStatus.appSettings["MaxLatencyAllowed"]);

}

Task 3: Access DetailsView or GridView Rows

The DetailsView class bound to a data source is convenient to display data from a SQL database table. However, we don’t have much control over the data on the rows at runtime. In the DataBound event of DetailsView class, you can use the following code to access text on each row and modify the row’s color:

System.Data.DataRowView rowView = (System.Data.DataRowView)this.EndpointDetailsView.DataItem;
if (rowView != null)

{
    for (int i = 0; i < rowView.Row.ItemArray.Length; ++i)
    {
        string endpoint = rowView.Row[i].ToString();
        if (endpoint.IndexOf("http") == 0)
        {
            // text in the row’s cell has string http
            ControlCollection c = this.EndpointDetailsView.Controls;
            DetailsViewRow row = this.EndpointDetailsView.Rows[i];
            // change the row color
            row.BackColor = System.Drawing.Color.LightGreen;

The same technique on GridView’s RowDataBound event:

const int latencyIndex = 5;

const int EnvIDIndex = 1;

if (e.Row.RowType == DataControlRowType.DataRow)

{

    int latency = int.Parse(e.Row.Cells[latencyIndex].Text);

    if (latency > _Default.MaxLatencyAllowed)

    {

        e.Row.Cells[latencyIndex].ForeColor = System.Drawing.Color.Red;

        e.Row.ToolTip = _Default.LatencyHighMessage;

    }

The only drawback is you need to know the index of the cell data to manipulate it. In the example code above, latencyIndex is a number. If you miscalculated the index and the string is not a number, int.Parse will throw a format exception.

The code coverage tools in Visual Studio have existed since 2005 in the Team Developer and Tester Tools -> Code Analysis Tools in Visual Studio Team System 2008 installation. However, there have not been enough articles about how to use them on Windows Service and WCF (Windows Communication Foundation) applications. The steps are not as easy as using the Test Run Configuration’s Code Coverage at http://msdn.microsoft.com/en-us/library/ms182496.aspx. You actually need to run the tools at command line to start and stop the code coverage monitor. I talked to the engineers in the Visual Studio team and compiled the official steps for doing code coverage on Windows Service and WCF applications. The biggest problem of the code coverage tools is that it does not support 64-bit code coverage collection. The reason is that there is no integrated solution for 64-bit code coverage collection in Test Run Configuration’s Code Coverage.  Visual Studio team decided to proactively deny instrumenting 64-bit assemblies for code coverage in Visual Studio 2008. The tool executables can be found at \Program Files (x86)\Microsoft Visual Studio 9.0\Team Tools\Performance Tools.

WCF application code coverage:

1.       Instrument the web service binary that you want coverage on: VsInstr.exe /coverage myWebService.dll. Deploy the dll to IIS 6 or 7.

2.       Start the monitor for collecting coverage data: VSPerfCmd.exe /start:coverage /output:”C:\CoverageData.coverage” /cs /user:”NT AUTHORITY\Network Service” /user should be whatever identity IIS is running under. /cs means cross session which allows the code coverage collection to be run from other sessions such as making a WCF call from a remote machine.

3.       Run the scenario or test cases that will exercise the WCF service.

4.       Verify the monitor has started: VSPerfCmd.exe /status:
PS D:\Users\hiliao> & 'D:\Program Files\VSCC\VSPerfCmd.exe' /status

Microsoft (R) VSPerf Command Version 9.0.30305 x64

Copyright (C) Microsoft Corp. All rights reserved.

Process and Thread Status

============================================================

Output File Name            : D:\tmp\CoverageData.coverage

Collection mode             : COVERAGE

Maximum Processes           : 64

Maximum Threads             : 256

Number of Buffers           : 258

Size of Buffers             : 65536

============================================================

Maximum Number of Processes : 64

Number of Active Processes  : 1

Global Start/Stop Count     : 1

Global Suspend/Resume Count : 0

------------------------------------------------------------

 Process                    :  d:\windows\system32\inetsrv\w3wp.exe

 Process ID                 : 6604

 Num Threads                : 0

 Start/Stop Count           : 1

 Suspend/Resume Count       : 0

============================================================

Users with access rights to monitor:

UserName (SID)

NT AUTHORITY\NETWORK SERVICE (S-1-5-20)

BUILTIN\Administrators (S-1-5-32-544)

NT AUTHORITY\SYSTEM (S-1-5-18)

PS D:\Users\hiliao>

5.       Shutdown the monitor when your scenario is done: VSPerfCmd.exe /shutdown
Waiting for process 6604 ( d:\windows\system32\inetsrv\w3wp.exe) to shutdown...

6.       The command does not return until you totally stop IIS for process w3wp.exe to exit. When the command returns. The code coverage data should be saved at C:\CoverageData.Coverage. Do not move the .pdb files of the instrumented EXE or DLL. Otherwise, C:\CoverageData.Coverage will fail to load.

Windows Service code coverage:

1.       Instrument the Windows Service executable that you want coverage on: VsInstr.exe /coverage WinSvc.exe. Deploy the exe to the Windows Service folder.

2.       Start the monitor for collecting coverage data: VSPerfCmd.exe /start:coverage /output:”C:\CoverageData.coverage” /cs /user:”Everyone”

3.       Start the Windows Service.

4.       Verify the monitor has started: VSPerfCmd.exe /status:
PS D:\Users\hiliao> & 'D:\Program Files\VSCC\VSPerfCmd.exe' /status

Microsoft (R) VSPerf Command Version 9.0.30305 x64

Copyright (C) Microsoft Corp. All rights reserved.

Process and Thread Status

============================================================

Output File Name            : E:\build73FST2.coverage

Collection mode             : COVERAGE

Maximum Processes           : 64

Maximum Threads             : 256

Number of Buffers           : 258

Size of Buffers             : 65536

============================================================

Maximum Number of Processes : 64

Number of Active Processes  : 1

Global Start/Stop Count     : 1

Global Suspend/Resume Count : 0

------------------------------------------------------------

 Process                    :  D:\Program Files\Product\PRODUCT Bulk Service\ProductBulkService.exe

 Process ID                 : 6768

 Num Threads                : 0

 Start/Stop Count           : 1

 Suspend/Resume Count       : 0

============================================================

Users with access rights to monitor:

UserName (SID)

\Everyone (S-1-1-0)

BUILTIN\Administrators (S-1-5-32-544)

NT AUTHORITY\SYSTEM (S-1-5-18)

5.       Run the scenario or test cases that will exercise the Windows Service

6.      Stop the Windows Service and Shutdown the monitor: VSPerfCmd.exe /shutdown. The code coverage data should be saved at C:\CoverageData.Coverage. Do not move the .pdb files of the instrumented EXE or DLL. Otherwise, C:\CoverageData.Coverage will fail to load.

If you can’t get any code coverage results, look at application event log (eventvwr.exe) with Source == VSPERF. There might be useful information about why the monitor is not running.

You can probably find x64 folder in \Program Files (x86)\Microsoft Visual Studio 9.0\Team Tools\Performance Tools. However, a necessary component VSCover90i.dll on 64 bit Windows is missing which causes collecting 64 bit code coverage to fail. The output message is from running the internal code coverage tools build at Microsoft. I am hoping the next release of Visual Studio will have the necessary DLL to run 64 bit code coverage.

I have been developing and maintaining an internal website at Microsoft IT which monitors the status of multiple master data management systems for almost 1 year. At the beginning of the development phase, I decided to use ADO.NET for querying and updating system status data. I was satisfied with the flexibility of ADO.NET 2.0. Testing the code was as easy as running queries in SQL server management studio 2005. Recently, I watched several videos at http://mtaulty.com/CommunityServer/blogs/mike_taultys_blog/archive/2007/05/10/9322.aspx about .NET integrated query which is a new feature in .NET 3.5. With the aid of Visual Studio 2008, building data model is as easy as few steps of drag and drop into the designer. Visual studio 2008 has a nice designer interface which uses code behind concept to turn database schema into C# code. It all starts with Add New Item -> LINQ to SQL Classes. The file extension is .dbml as you can see in the videos. All I had to do to setup the class was drag the table from Visual Studio’s Server Explorer and drop it to the .dbml designer page.

The next step is to find out the class name of the code behind page. If the .dbml filename is WebServicesSettings.dbml, the code behind file would be WebServicesSettings.designer.cs. Inside the code file, you would find WebServicesSettingsDataContext class inherited from System.Data.Linq.DataContext. The class enables you to manipulate the data in the database. In the example below, I will show you how to query a string value from table EnvironmentEndpoints and use it as the SQL server hostname to connect to another database to query 4 other string values which are MSMQ endpoints. When the 4 MSMQ endpoints are acquired, the code updates the EnvironmentEndpoints table with the 4 MSMQ endpoints with command EnvEndDC.SubmitChanges();

    byte envID = kvp.Key;

    try

    {

        // the connection string in web.config is used for the default constructor

        EnvEndpointsDataContext EnvEndDC = new EnvEndpointsDataContext();

        // Very useful command similar to SqlCommand.ExecuteScalar

        EnvironmentEndpoint endpoint = EnvEndDC.EnvironmentEndpoints.Single(end => end.EnvironmentID == envID);

        SqlConnectionStringBuilder sqlConSB = new SqlConnectionStringBuilder();

        // build the connection string to connect to the MSMQ endpoint database

        sqlConSB.DataSource = endpoint.SQLServer;

        sqlConSB.InitialCatalog = "ConfigurationStore";

        sqlConSB.IntegratedSecurity = true;

        // example of using impersonation

        ServiceStatus.impersonated = ServiceStatus.impersonateValidUser(serviceAccountUser, serviceAccountDomain, serviceAccountPassword);

        if (!ServiceStatus.impersonated)

        {

            // impersonation failed

            string message = DateTime.Now + " - Impersonaion failed. Continue updating MSMQ endpoints...";

            Trace.WriteLineIf(ServiceStatus.debugSwitch.TraceError, message);

        }

        // connect to the MSMQ endpoint database

        WebServicesSettingsDataContext WebServiceDC = new WebServicesSettingsDataContext(sqlConSB.ToString());

        // WSSetting is a local variable name to the LINQ query for the Single command

        // What I am doing here is querying the row which has column ‘Name’ ServiceAsyncAddressSecondServer

        WebServicesSetting ServiceAsyncAddressSecondServer = WebServiceDC.WebServicesSettings.Single(WSSetting => WSSetting.Name == "ServiceAsyncAddressSecondServer");
        // Update the values in EnvironmentEndpoints table

        endpoint.CorpNetAsyncWebService = ServiceAsyncAddressSecondServer.Value;

        WebServicesSetting AcknowledgmentServiceAddressSecondServer = WebServiceDC.WebServicesSettings.Single(WSSetting => WSSetting.Name == "AcknowledgmentServiceAddressSecondServer");

        endpoint.CorpNetAckWebService = AcknowledgmentServiceAddressSecondServer.Value;

        WebServicesSetting ServiceAsyncAddress = WebServiceDC.WebServicesSettings.Single(WSSetting => WSSetting.Name == "ServiceAsyncAddress");

        endpoint.ExtraNetAsyncWebService = ServiceAsyncAddress.Value == ServiceAsyncAddressSecondServer.Value ? string.Empty : ServiceAsyncAddress.Value;

        WebServicesSetting AcknowledgmentServiceAddress = WebServiceDC.WebServicesSettings.Single(WSSetting => WSSetting.Name == "AcknowledgmentServiceAddress");

        endpoint.ExtraNetAckWebService = AcknowledgmentServiceAddress.Value == AcknowledgmentServiceAddressSecondServer.Value ? string.Empty : AcknowledgmentServiceAddress.Value;

        if (ServiceStatus.impersonated)

        {

            ServiceStatus.undoImpersonation();

            ServiceStatus.impersonated = false;

        }    

        // LINQ runtime generates a SQL update when the line is executed

        EnvEndDC.SubmitChanges();

    }

    catch (Exception ex)

    {

        string message = DateTime.Now + " - Failed to update MSMQ endpoints on Environment ID " + envID + " -> " + ex.GetType() + ": " + ex.Message;

        Trace.WriteLineIf(ServiceStatus.debugSwitch.TraceError, message);

    }

    if (ServiceStatus.impersonated)

    {

        ServiceStatus.undoImpersonation();

        ServiceStatus.impersonated = false;

    }