Pair Usefully and Code Effectively

Pairing is of real value when two developers work with each other in a such a manner that they allow the other person to teach and learn new ways of working. This mutual learning process will ensure that the competency of the team will grow uniformly. In my current job we almost never work alone we always pair. Recent retrospectives have been focussing on how we get the most out of our pairing sessions. Some developers said we don’t swap pairs enough, there were questions about how and when do we determine it is a good time to swap pairs.

Well there is probably no hard and fast rule on pairing but some of the things we seem to recognise in a team are as follows.

1. Story Champs - A story owner or champion should be present on the story who will see the story go through the board

2. Story Progress - Having a story champion will allow you to swap pairs across a story reasonably well without affecting the progress of the story.

3. Keyboard Policy – More often than not this is a reason for frustration among developers in a pairing session. Use TDD to pair effectively.

Eg. Pair made of Dev A and Dev B.

• Dev A writes test to fail – Red
• Dev B implements code to pass the test – Green
• Dev A refactors the code

Alternate between the devs in this cycle will ensure pairing sessions are not driven by just one dev

4.Pairing Overdrive - If at any point during a pairing session one of the two seem to be dictating code for more than a few minutes ( I call this overdrive mode). You should really stop pairing and determine if the pairing session is useful and how it can be made useful , the dev who is on overdrive mode should really take the initiative to bring his/her pair up to speed on the story they are working on and discuss any gaps in each others understanding.. get away from the computer go for coffee break.. really helps.

5. Check-in frequency – When we pair due to reasons beyond our control one of the two dev may have to leave at any time before the other, frequent check-ins will allow you to make sure your CI is effective and also that you can switch machines quickly and effectively.

6. Computer Policy - if a pair is working on machine and dev who owns the computer has to leave, the other dev should be able to continue working on the story ..In such a situation it helps to leave the computer unlocked till your pair can make a check-in and then pull the changes on his computer and continue work, locking your computer and leaving could really be annoying to some one who really wants to continue work.

7. Early Birds –If you come in earlier than your pair, instead of just picking up the story and continuing work it helps to look at your CI server and fix any broker builds. If you do work on the story do make sure you explain what has been done and how far you have progressed so your pair gets up to speed, else you end up with Pairing Overdrive.

8. Privacy Policy – If you are working on your pairs machine and when your pair is not around do not snoop around there mail or respond to IM that they receive even for fun, what seems to be fun may turn out to be an annoyance. Finally there is absolutely no need to get personal during a pairing session, every developer has his own style and strengths it is important to respect that , for all you know they might be really skilled in areas you are not so good yourself..

After every stand up it makes sense to discuss who can swap pairs. Infact before a stand up it helps to be in a checked in state if you want to make sure your team can swap pairs every day

For now this is all.. code carefully and pair usefully  :)

Acceptance Testing

After playing around with Cucumber/ Cuke4Nuke and Specflow.. turns out cucumber is the winner for me.. Cuke4Nuke took me a while to get going and seems considerably slow and is behind cucumber by some distance..

Specflow is alright however the idea of using attributes to match my step definitions is what i didn't like.. integration with VS and being able to use the NUnit test runner are clear winners.. the entry barrier to this is pretty much minimal.

Well as for Cucumber/ Ruby / WATIR, the idea of using RubyMine to write my tests and debug them in the same doesn't make me miss VS integration and debugging.. I don't think i particularly miss writing my tests in different languages.. well i never do so why bother… The choice of gems available for Ruby and dynamic nature of ruby is something that makes the effort rewarding .. Build integration using a Rake runner is easy not much effort either..One other reason is may be because i use this at work .. there is yet one more to be looked at which is the WebDriver API for Selenium 2.0. http://google-opensource.blogspot.com/2009/05/introducing-webdriver.html ..

I took some time to play around with these since I don’t like skimming through the surface ..

SqLite Manager plugin for firefox

There is a good chance some of you use this or know about this already. However this is kind of new stuff for me.. In my current project we use SqLite  to run our integration tests for the repository tests and the some of the rhino ETL process classes. We use SqLite as a file based database rather than an in memory instance and while i was debugging through the code I hit a point where i wanted to see how the schema was created and the data stored, so i can be sure the foreign keys where stored with the right values

SqLite Manager is a useful plugin for Firefox 3.6. This is browser based and allows you to work on the file based database just like Sql Server Enterprise Manager allows you to work with SQL 2000. This is a really useful tool when you are writing integration tests with SqLite.

You can get the plugin at , you may need firefox 3.6 or above

https://addons.mozilla.org/en-US/firefox/addon/5817

NUnit - Teamcity - TestCaseSource tip

If you are using features from NUnit 2.5 or above TestCaseSource attribute may sound familiar. This is a very useful feature in NUnit now which helps us reduce the clutter of repetitive code in our test class. I am sure everyone can see how this can be done on the NUnit website as well , but the point of this post is in relation to a problem I ran into when I used the TestCaseSource attribute. To elaborate on this let me use a simple example of a class which calculates the square of an integer.

public class SquareOfNumbers
{
   public static int Square(int x)
{
   return x * x;
}
}

When i first started writing tests i used the TestCaseSource attribute , so my test class looked like the one below

[TestFixture]

public class SquareOfNumberFixture
{
private static readonly Dictionary<int, int> _testData = new Dictionary<int, int>();

public static Dictionary<int, int> TestData
{
   get
   {
       _testData.Add(2, 4);
       _testData.Add(0, 0);
       return _testData;
   }
}

[Test, TestCaseSource("TestData")]
public void Test(KeyValuePair<int, int> keyValuePair)
{
   Assert.That(SquareOfNumbers.Square(keyValuePair.Key ), Is.EqualTo(keyValuePair.Value));
}
}

These tests run successfully, but when run as part of my teamcity build there is no detail about what the tests where as in there was no reference to the name of my test method. I did spend sometime trying to fix this and found a couple of issues.

1. Team city was not using the same nunit version that I was using to write tests, so the plugin had to be updated on team city, this way i made sure the build uses the same nunit framework as my source code does

2. I changed my tests to use TestCaseData class in conjunction with the TestCaseSource attribute, this allowed me to specify a name for each test scenario , so after refactoring the test class , I can now see the test names on the nunit test report generated by Team city, the code for the new test class is shown below

In addition to fixing the problem , TestCaseData class made the test code more readable.

[TestFixture]
public class SquareOfNumberFixture
{
  public static IEnumerable TestData
  {
      get
      {
          TestCaseData squareOfZeroTest = new TestCaseData(0).Returns(0);
          squareOfZeroTest.SetName("SquareOfZeroReturnsZero");
          yield return squareOfZeroTest;

          TestCaseData squareOfIntegerTest = new TestCaseData(2).Returns(4);
          squareOfIntegerTest.SetName("SquareOfTwoReturnsFour");
          yield return squareOfIntegerTest;
      }
  }

  [Test, TestCaseSource("TestData")]
  public int TestSquareOfNumbers(int x)
  {
      return SquareOfNumbers.Square(x);
  }
}

On second thoughts further refactoring the class makes it more readable if i had done the following…

[TestFixture]

public class SquareOfNumberFixtureNew
{
  [TestCase(0, Description = "SquareOfZero", Result = 0)]
  [TestCase(2, Description = "SquareOfTwo", Result = 4)]
  [Test]
  public int TestSquareOfNumbers(int x)
  {
           return SquareOfNumbers.Square(x);
  }
}

Acceptance Testing – Cucumber? Specflow? Cuke4Nuke

I have been pretty much dormant on this blog due to my part time MBA coupled with a some tight deadlines at work. And to get me back into the blog bandwagon I just thought I will do this small pet project of mine outside work for which I have been exploring the acceptance testing tool to use infact functional test tool which will allow me to translate my acceptance criteria on stories to tests from plain english.

I found something about Specflow on a few blogs,it is a set of libraries to write specifications using Gherkin. You can check the screencast here or read this post from Ryan Lanciaux. SpecFlow can use either NUnit or MsTest as the engine. You could use specflow and drive WATIN.

Being a .Net developer I am quite inclined to use Specflow and Watin after having had a look at it mainly because i dont need to learn a new language and i can use my c# knowledge to write tests, However previous experience with WATIN a couple of years was not great and it always seemed be behind some of the things you could do with WATIR, hopefully this has changed now, In my current job we use Cucumber + Watir to write acceptance tests and we use Ruby, Although I found it a bit steep on the learning curve initially and mainly because i havent worked in anything but .Net. Now after a couple of weeks into it I am beginning to think if this is may be the right choice, for e.g I am not even a novice in Ruby but RubyMine from JetBrains makes it easy when you are a new bee.

I still didnt want to give up exploring a .Net + cucumber combination and my search led me to this article by Richard Lawrence in his blog which compares the pros and cons of Watir and Watin.. go to . Interestingly Richard and a group of other people started driving this project called Cuke4Nuke sometime ago now which should allow us to write tests in C# for cucumber, That sounds great to me, because I am not looking at any advanced usage of cucumber, i guess my needs are pretty basic for now, I have not used it yet but all i can say at the moment is having looked at the screen cast and the background the creators of the project have given it quite a bit of thought on performance (if you read the blog you will find that they did explore using Iron Python over WATIN which was horribly slow).

A couple of months ago they released 0.3 which supports almost everything you can do with Cucumber in Ruby or Java, making C# a first class language for Cucumber. (The only missing features are small things like tags on Before and After hooks and a richer Table object.)

To install and have a play with this go to the Cuke4Nuke Wiki at http://wiki.github.com/richardlawrence/Cuke4Nuke/

Screen Cast on Cuke4Nuke and WATIN

http://www.richardlawrence.info/2009/12/03/screencast-testing-web-applications-in-net-with-cuke4nuke-and-watin/

I am going to give this a go for a spike on my new project so lets see how this goes :).

Nant Task for Sandcastle

I have been thinking of writing a Nant task for Sandcastle for quite some time so I decided to knock something up . I have been fairly busy at work and havent been able to spend time on this. As i find some time on the train I just finished this piece of code.

I am quite a fan of Nant and the Nant contrib project has a task for NDoc which kind of inspired me to do one for Sandcastle. Sandcastle supports the new frameworks in .Net quite well and most people who were using NDoc would have migrated to Sandcastle due to its capabilities for build purposes.

This task is intended to allow users who do not want to use sandcastle command line builder in there nant scripts as an external process. The logging of this task and the sandcastle output is also streamed into the nant log.

I have based my task schema on the bare minimal that will require direct configuration in nant. In any case you should be able to do all the configuration in the sandcastle project. What’s shown below is purely a because i am a developer and I need these features and so i think everyone is going to be happy with it :). '

The following readme is placed in a text file along side the installer zip file.

The Sandcastle for task is built using the following components
Nant 0.86
Sandcastle Help File Builder
Sandcastle UI Builder

The core components required by the task are installed by the installer.

The installer allows you to install the task into a folder that you choose but does not check to see if Nant is installed in the same directory
Generally C:\Program Files\Nant\bin
Installing the task in the same folder as Nant is the only scenario that has been tested.

The path of nant should be added to the path variable as instructed in the Nant installation instructions

In addition to installing the task the following configuration for the Nant.exe.config file needs to be added.

Under the elements
<configuration>
...<nant>
......<frameworks>
...........<platform>
................<task-assemblies>
                    <!-- Nant sandcastle task-->
                  <include name="NAnt.Contrib.Tasks.Sandcastle.dll"/>
If you wish to add the Sandcastle task into another folder, the Nant probing paths need to be set to look at this folder. It is not recommended however

Source code is also provided and feel free to customise it or edit it , The source code is present at Install folder\sandcastle task\Src

I have tested this on my system by installing sandcastle, nant and this task and it works fine. Obviously i am saying “Works on my machine”, if you see any problems using it please let me know about it.

The Sandcastle task schema for the Nant script should be as below, project and output are the only two required attributes,

<sandcastle 
    project="${Sandcastle project file path}" 
    output="Output location for Sandcastle files">

    <showMissing 
        remarks="false" 
        params="false" 
        returns="false" 
        values="false" 
        namespaces="false" 
        summaries="false">
    </showMissing>
    
    <document 
        internals="false" 
        privates="false" 
        protected"="false" 
        attributes="false"
        copyrightText="" 
        feedbackemail="" 
        footer="">
    </document>
</sandcastle>

e.g Nant build file

<?xml version="1.0"?>
<project name="Hello World" default="build">
    <property name="projfile" value="C:\Documentation.shfb"/>
     <target name="build">
        <sandcastle project="${projfile}" output="C:\Documentation\Help">
<document copyrightText="Copyright@ TSQLDOTNET Limited" feedbackemail="srinivas.s@tsqldotnet.com"/>
 </sandcastle>
    </target>
 </project>

Link: Nant Sandcastle Installer

The download consists of the prerequisites hence it is bulky at 40MB, The prerequistes include Sandcastle installer , Win 3.1 installer and DotnetFx

Google Chrome

Now as is all over the news i went about downloading the browser to get a feel of it. The download of the click once installer was about 474 KB so how big is that :) really neat start, then the download of the installer and install takes about 1 minute (4 MB line) and in another minute it imports all settings from IE. Now that was really impressive , two and half minutes all set and up and running.

Features that clearly stand out are the Search history, Dynamic Tabs and the simplicity of book marking pages, there is more but these make be happy already :).

A useful thing is the Search your history box, I have wished for something like this for ages and its nice to see this feature. Hope Google does this for favourites as well.. I having accumulating favourites for the last seven years and i some times wish i could search through surely useful to me :)

The UI is definitely better than the heavy IE7, tabs are not new in a browser these days just checkout the dynamic tabs feature in Google Chrome, it is definitely cool , drag the tab out and see how it works

Bookmarking is easier and the download feature is different to other browsers.

Seems like Google has just started , I am already thinking of using this browser , but i am not sure about any bottle necks .. gotta wait and see

I am quite happy with what the beta offers,  if Google manages to hold off IE , I bet we could see this being used more widely..

If you want to download go to http://tools.google.com/chrome/?hl=en-GB