MS DTC Timeout error

I had a very frustrating Friday evening fighting with MSDTC. I made a one-line, 10 second change to a page I was working on. It was one of those things that you really don't even need to test usually, but I always test, no matter how small the change, and 2.5 hours later I was still pulling my hair out. I just kept getting MSDTC timeout exceptions.

Now, this was a page that had been working literally hours before, with no other code changes. The ONLY difference I could think of, was that I had applied windows updates to my machine - but this turned out to be a red herring. The same page, with the same code, worked on a colleague's machine. I checked settings, triple checked settings, flushed my DNS cache, restarted my machine, all to no avail. Comment out the TransactionScope - it all worked fine, put it back in, boom!

Anyway, in case this happens to anyone else ever - this turned out to be a DNS issue on the SERVER. Logging into the server I could ping my machine by IP, but pinging by host name failed. Finally, I was getting somewhere. It turned out there was a dodgy DNS entry - flushing the DNS cache on the server worked and everything returned to normal. What a waste of 2.5 hours.

Moq :: Ignoring Arguments

I've always used Rhino Mocks as a mocking framework, but at work we recently made the decision to give Moq a try.

My initial reaction is: WOW! It is just SO much easier to use. I've always found the setting up of mocks and verification of method calls a tedious task, but using Moq I've actually found it's really simple. It's a far more intuitive framework, and once I've got around my Rhino Mock habits, I've really found that the amount of code required for mocking is drastically reduced.

One very simple thing that stumped me today though, was trying to verify a method was called, but telling Moq to ignore the argument that was passed. In this case Rhino Mocks is a little more intuitive - it has an IgnoreArguments() method that chains off the setup. In the end though, the Moq implementation is actually easier - you just make your Setup or Verify call and use the "It" class to generate your stub.

In my example:

  myMockedClass.Verify(x => x.Connect(It.IsAny<MyArgumentType>()));

.NET Assembly Probing

I hate the way Windows Forms applications get built with all their binaries in a single folder. I also hate the publish options in Visual Studio - those crappy .application files stink in so many ways. I prefer to just deploy the executable and related assemblies using some kind of packaging tool.

The problem here is all the dll's by default need to be in the base appdomain directory, which can end up being a horrible mess in the base install directory. There is a configuration option you can use with your application, though, to tell it to search in other folders for required assemblies, like so:

WatiN with CruiseControl running as a service

We've started using WatiN for our automated tests: nice and easy to use and integrates easily, but I did hit one stumbling block: CruiseControl.NET. When running tests locally, there were no issues - check the code in and bang, the tests fail. It was immediately apparent that it was a security thing - the CruiseControl.NET service runs by default with the SYSTEM user, but I could find little to no help anywhere on how to set this up correctly.

One solution was to just tick the service option to "Allow service to interact with the desktop", but this didn't work for me - the failure remained the same when the browser instance was being created.

It took a few hours of testing (I ended up using a local Scheduled Task to test this out) and I finally found a fairly easy way to get it to work - on your build server you need to use a local account that the service runs under. I used a local admin account - you might not be able to do this in which case you're on your own (it'll still work - you'll just need to be more careful about how you apply permissions), but the steps to set this up are as follows:

• Create a local admin account (e.g. CCAdmin) - make sure you set it so the password does not need to be changed and does not expire
• Log out, and log back in using the new account
• Open up IE (or whatever your testing browser is) and go through all the dialog screens. Set the home page to blank. If you're using Firefox, make sure all the required plugins are installed.
• Open up services.msc (Start...Run....services.msc), and stop the CruiseControl.NET service. Right-click and go to Properties
• Go to the Log On tab, and instead of a Local System account, set it so the service uses your new account
• If you have not created an admin account, make sure the account has all necessary security permissions
• Click OK, and fire up the service again

WatIn

I've been fighting with Selenium and automated testing lately, and I just couldn't shake the feeling that it just wasn't the right tool for the job. The IDE is flakey in terms of files you save (making changes to the project often results in JS errors in the tests), the server is a java server which I had to jump through hoops to get running as a Windows service, and the loading of a browser for the tests is hellishly slow.

It really is a great tool, and I love it's ease of use for development (I use it to autocomplete forms instead of typing all that crap in over and over again), but as an automated testing suite on a Windows technology stack, I'm just not a huge fan.

So today, I downloaded WatIn and gave it a run. I had the automated nUnit side up and running in a matter of minutes - the tests ran fast and the API is intuitive and easy to use.

The test recorder is not as good as Selenium's, but it's decent enough, and there is a beta version out that is supposed to be a vast improvement. I did download and try the Beta version, but it wouldn't even run for me, so I guess it's REALLY in Beta. Anyway, I'm more interested in the CruiseControl automated side of testing than visual testing, so it's easy, understandable unit test code that I want to be able to produce - and for this WatIn wins hands down.

Running Selenium RC as a Windows Service

We've recently started using Selenium as a testing tool at work. The IDE is great, particularly for filling in forms during development, but I'm a stickler for automated testing.

Selenium does off Selenium RC, which combined with nUnit allows for this in a variety of programming languages. The problem here, is that the server is a jar file, and I wanted it running as a windows service on our build server.

Anyway, I found a great article on tacktech.com that shows how to run just about anything as a windows service - and I successfully used that article to get Selenium RC running as windows service on our build server. Here are the steps:

1. Install the latest Java runtime if you don't have it installed already
2. Install the Selenium server (e.g. C:\Selenium\selenium-server-1.0.1
3. Download srvany.exe and instsrv.exe (these are part of the Microsoft Windows Resource Kit - you will need to download the correct version for your OS) and copy these files to a location on your server (e.g. C:\reskit)
4. Browse to this folder, and type: instsrv "Selenium RC" "C:\reskit\srvany.exe" - this will create the windows service named "Selenium RC", which will now be installed as a Windows service, although it won't start up yet
5. Open up regedit, and browse to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Selenium RC
6. Right-click "Selenium RC" in the tree, and click New - Key, and add a key called "Parameters"
7. Open Parameters, and create a new string value called "Application"
8. Add the following to the data value for the new string value: "C:\Program Files (x86)\Java\jre6\bin\java.exe" -jar "C:\Selenium\selenium-server-1.0.1\selenium-server.jar", substituting paths to the java exe and the selenium server jar file where appropriate
9. Load up the windows services console (services.msc) and start the service

SQL Server: Finding tables by column

Assuming you use a decent naming convention in your database, it's sometimes useful to be able to find a list of tables with a common column - for example if you want to write a script to clean out all data related to a specific item, referenced by foreign key columns of the same or a similar name.

 
SELECT distinct
    c.table_name,
    c.table_schema,
    c.column_name
  FROM 
    information_schema.columns c
    INNER JOIN information_schema.tables t 
      ON c.table_name = t.table_name 
  WHERE
    c.column_name LIKE '%my_column_name%'
    AND t.table_type = 'BASE TABLE'
  ORDER BY 
    c.table_name,
    c.column_name