Reducing Unit Testing Friction…

June 26, 2008

Gears.jpgIt doesn’t matter if you’re a TDD purist or a test-as-you-go guy, having a quick way to execute the tests that you’ve created is critical to them actually getting run as regularly as they need to be. To that end, here is the current setup that I’m using to make this as easy as possible.

Everyone knows that I’m a sucker for a new tool but this tool has been with me for quite a while and I’m skeptical that anything will be able to replace it. TestDriven.Net is the foundation of a great workflow when it comes to unit testing and it’s truly worth the small amount that Jaime asks for his efforts. He’s a great guy and it’s a great tool – go buy it and install it immediately.
So now that you have it installed, there a couple of settings in Visual Studio that help make that test/code/test cycle even tighter.

Keyboard shortcuts

Once you have TestDriven installed, you’ll notice some extra options in the context menus when you right-click on class files, projects and even in code. These will allow you to run tests in various fashions but I’m a lazy man and I hate moving my fingers off the keyboard so I’ve added a few shortcuts to Visual Studio. In the options menu for “Keyboard”, I bind Control-1 to “TestDriven.NET.RunTests”, Control-2 to “TestDriven.NET.ReRunWithDefault”, and Control-3 to “TestDriven.NET.ReRunWithDebugger”. The way this helps me is that I am able to use Control-1 to execute the test that the cursor currently resides in (if you’re in between tests or on the fixture itself, it will run all in that fixture). If it doesn’t pass, I can hop over to the code that’s being tested, make the changes and then just press Control-2 to see if the test passes. No back and forth between the two. The last shortcut is helpful because it allows me to set a breakpoint where I am (using F9 of course) and rerun the test so that it will hit that breakpoint. Again, no back and forth.

Output window

Every time you execute a test, the tool bar will give you a quick look at the status but the output window will be your friend when things don’t quite execute as planned. All the output gets piped here but you don’t need it in your face so be sure that the “Show Output window when build starts” is unchecked but also be sure that you have it collapsed just below your code file. output window.jpg This way if you do have need to see what is in the output, you can just press Control-Alt-O and it will pop up with focus. (Pressing Escape will cause it to hide again and leave us in our code.)

I still haven’t quite figured out how to bind to the “Run All Tests” so if you have a suggestion, I’d love to hear it. However, I do still find it helpful that a “Run All Tests” will execute again when using the rerun shortcuts and I use that quite a bit right before commits. (If you’re not religious about running ALL tests before a commit, I hereby grant your co-workers permission to knee-cap you.)

Because unit tests only provide benefit when they are actually run, we need to do everything that we can to tighten the code/test loop and make executing the right thing at the rightht time as easy as possible.


David O’Hara is a Principal Consultant with Improving Enterprises in Dallas, Texas.

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Announcement: DDNUG – Automated Testing with Visual Studio 2005

June 6, 2007

Apparently, they’re going to continue to allow me to get up in front of people and talk since it turns out I’m not half bad at it. I’ll be presenting a the Dallas .NET User Group on June 14th so head over and sign up – the pizza is free and, at worst, you’ll get to laugh and heckle me. The talk is being billed as programmer testing since I’m not going to stick to strict Test Driven Development (I’ll explain why in the talk). I’ll cover the basics and principles as well as MSTest, NUnit, RhinoMocks, and TestDriven.Net. Heck, I may even grab someone and doing a quick round of the TDD Pairing Game if I’m feeling randy.

Once again, I’m a little nervous too but that’s what makes it fun. Hope to see you there.

UPDATE: I’ve posted here for the presentation content.


TDD Experiences and Thoughts…

December 5, 2005

While still only a relative novice to TDD, I’ve found it to be amazingly helpful in building better classes and thus writing better code. With no one to guide me, I stumbled thru several articles and numerous examples before I finally started to “get it?. There has been quite a bit of trial and error that has caused me to alter the way that I code and I wanted to write about a couple of things that I’ve started doing that have been a tremendous help.

Throw out the debugger. Ok, not really, but that’s sort of how I’ve started to feel now. Actually, this has been the biggest shift in my paradigm and thus my actions (aside from the general need to refactor my classes as a whole). I used to write a small console or windows app that would instantiate the class(es), do some sort of setup, and then respond to my input so that I could see how my code was evolving/reacting. Well, this is EXACTLY what unit testing does. It’s simple, I know, but it still took me some time to get used to and to wrap my mind around the fact that I didn’t have to press F5 to see how things were coming, I just ran my tests. As I wrote more tests, I wrote more code to use those tests and vice versa. It was a wonderfully vicious cycle that led to some pretty enormous tests with a ton of pre-condition and post-condition checking.

Refactor your tests and fixtures as much and often as needed. While I had some extensive unit testing being done, it certain didn’t follow DRY and was sort of a mess to maintain. Enter SetUp/TearDown… While there are still some who debate their use, others seem to agree with me that using them will not only make your life easier but makes your code cleaner. Whenever I have a test that needs some setup done, I usually refactor that setup into its own private method first. Once several of the methods use that single private method, I move them all to a separate fixture and make the private method a “SetUp? method. As a side note, good naming convention is VITAL for good tests. I avoid using the suffix “Test? for them and try to make them as descriptive of what they’re testing as possible. This reduces the number of messages that I have to output with my Asserts – oh, and always try to adhere to OAPT for better testing.

Finally, for those of us who use log4net (if you’re not using it, start NOW) I’ve put together a quick little way to leverage it in unit tests (see example below). By setting up and adding a ConsoleAppender in my TestFixtureSetUp, I get all of my messaging within my testing GUI. I’m even able to control the levels and formatting on a per fixture basis. Notice the use of preprocessor directives to keep the logging out of my automated build scripts as well.

[TestFixtureSetUp]
public void FixtureSetUp()
{
#if !AUTOMATED && DEBUG
AttachConsoleAppender();
#endif
}

private void AttachConsoleAppender()
{
LevelRangeFilter rangeFilter = new LevelRangeFilter();
rangeFilter.LevelMin = Level.Debug;
rangeFilter.LevelMax = Level.Info;
ConsoleAppender appender = new ConsoleAppender();
PatternLayout layout = new PatternLayout( “%date %-5level %logger – %message%newline” );
appender.Layout = layout;
appender.AddFilter( rangeFilter );
BasicConfigurator.Configure( appender );
}

Which finally brings us to the testing GUI itself – learn it, live it, love it. While the NUnit GUI is passable, I’ve found Zanebug to be everything it is not. Plus it’s FREE – can’t beat that…