Anthony Dahanne’s blog

Mardi dernier, à 18h30 avait lieu dans les locaux d’Octo un Barcamp sur Java.
J’arrive un peu en retard, 18h40, et rien n’a vraiment commencé, les participants, qui s’étaient au préalable inscrit sur le site du BarCamp Java Paris, arrivent peu à peu.
Je reconnais des visages, des connaissances que j’ai rencontrés aux XP Days France 2008, parmi eux Gregory qui m’apprend l’existence du site StackOverFlow, créé par des gourous de .NET (argh) qui permet de poser une question technique, un peu à la Yahoo answers, mais orienté développeur (tous langages, ouf !); avec un fort accent sur la communauté : on gagne des points quand on répond bien et souvent, ce qui permet de modérer ensuite les questions des autres, etc… allez voit ce site, c’est super bien fait, j’ai déjà posé ma question cet après midi sur Hibernate et j’ai eu une réponse en 45 minutes !
On était bien une quarantaine quand l’organisateur, Luc Bizeul, prend la parole et nous invite à nous présenter (prénom, nom, 3 tags)
La plupart des personnes présentes étaient intéressées par Spring, la SOA, JEE.
Après ces présentations, Luc nous a invités à remplir chacun un post it avec un thème que l’on aimerait aborder pendant ce BarCamp.
Les post-it remplis, et triés par thème si les sujets étaient récurrents, on voit apparaître beaucoup de TDD, Usine logiciel, communauté Java Paris, les licences Open Source, et un peu moins d’autres (j’ai oublié…).
Une fois ces regroupements faits, Luc demande pour chacun des thèmes qui est intéressé; et selon le nombre de personnes intéressées, il attribue une salle pour chaque sujet (4 salles sur 2 sessions, donc 8 sujets ont été choisis).
Je choisis la salle TDD, et on a défini TDD, les avantages, qui en fait (sur une quinzaine de personnes on était 2 ou 3 à en faire !) comment l’appliquer sur JSF (apparemment un dénommé Wicket existerait pour çà) aussi sur GWT (pas satisfaisant non plus, à creuser..).
Un pointeur intéressant a été évoqué le livre de Kent Beck sur la TDD : Test Driven Development: By Example.
Et là il était 20h, et je ne pouvais pas rester … dommage…
Dommage car les sujets évoqués étaient intéressants, pas plus techniques que cela, surtout orientés agilité; de plus, on a beaucoup à partager avec les personnes présentes sur ce genre d’événement !
J’étais le seul consultant de Valtech à ce BarCamp; et oui, la majorité d’entre eux préparaient les Valtech Days 2008 qui auront lieu les 21 et 22 Octobre !

I began this second day with a presentation of Rspec, Behaviour Driven Development and Selenium Grid, by Jean Michel Garnier. He told us about the history of software testing, Test Driven Development and Behaviour Driven Development.
So what is TDD against BDD ? Quite the something, from a technical point of view; but in fact it diminishes the distance between the client and the software engineer.
BDD is about writing sentences to describe tests.
A story (from Dan North point of view) (As … I want … To …)is divided into scenarios ( Given … When … Then …).
The thing is, the people who write specs “could” write Rspec classes, but the syntax is still a bit technical …
Then Jean Michel told us about Autotest, a framework to automatically run tests when you modify a source code; Rcov a software to measure code coverage of your tests (gem install rcov ; rake spec:rcov and finally Heckle, a framework that modifies your source code to … check that your tests are useful !

Next, I’ve seen a presentation of the origins of Agile methods; introducing the Agile Manifesto, agile principles,agile methods like Scrum (3 actors : product owner, scrum master and the team; product backlog to prioritize stories, sprint backlog to split stories in different tasks, and the sprint; and eXtreme Programmingwith its values simplicity, respect, courage, etc…)
The orator also remind the audience about older, predictive methods like cascade and V…

I’ve also attended a session proposed by Guillaume Carré, from Xebia presenting unit tests and Easymocks, where the audience was able to distinguish stubs from mocks, mocks being more faithful to the real behaviour of the class.
Easymock uses interfaces to create mocks, so you get all the mock coding job done !(but you have to describe the behaviour of your mock object).
The orator also talked about Mockito, from ThoughtWorks, which gets the description of the mock object according to the method called on this mock; you still describe the behaviour of the mock, but this time you verify the value returned at the end of your test, not before (which makes test code more readable than Easymock).

To finish the day, Jean François Helie, from Octo coded in front of us a blog engine, based on hibernate, maven, Spring, and Spring MVC but … using a test driven approach.
Jean François used Java 5 annotations to describe JUnits tests and once the tests were done, coded the application classes.
He first wrote code for the DAO classes, using Hibernate entity beans annotations (it looks so good persistence without XML).
Then he decided to lighten the test class code with Spring 2.5, using annotations to autowire bean dependencies (yeah annotations look good)
Once the model was written, he continued to the service, writing the test first, of course, but also using mock objects to be able to distinguish errors from the model to errors from the service class; for that he used Easymock linked with Junitils4 with annotations.
Finally, he wrote the controller, always writing the test class first, using Spring MVC framework (specifying the url mapping in the controller class)
The demonstration was quite impressive, I really enjoyed that one! (it reminded me that Java is still on !)

My colleagues from Valtech were not on holidays this second day, they presented Test Driven Requirements, using Fitnesse; continuous integration with Hudson (getting very popular now) and contracting Agile projects.

These XP day(s) were a great experience, I really hope I’ll be there next year !

This Monday 5 and Tuesday 6 of May 2008, I’ve been to my first XP Day(s, it actually lasts 2 days) in Paris, an event organized by the association XP France; here are my impressions…

At 8:30, slowly, every guest gets his ID tag, and a breakfast is offered, we’re discovering the schedule of the days to come: the event is divided into 4 rooms, and each day is divided into 4 1 hour and a half sessions (but a session can last all day long or also half a day); all sessions are in French language.
Many subjects are present, the advantage is that you’re sure to find something interesting; on the other hand, if 2 appetizing meetings take place at the same time, you have to choose.
Then, at 9 o’clock, we’re about 150 people (I think) and we are asked to go downstairs, to attend the introduction meeting where the organizers of the event introduce themselves (and also ask people to, if they can, contribute for the next XP days) and the following XP meetings (Agile Tour, round France, and Agile Open, where attendees will be able to turn into speakers); finally, the speakers of the day introduce what they will be talking about during the sessions they will present.
I chose to be present at the XP laboratory, presented by 2 folks working at Pyxis (a Quebec based company responsible, among others, of Green Pepper).
The session last all day long (but you’re free to leave or get back when you want) and invites people to work on a refactoring of the Miles card game (“1000 Bornes” in French), called XtremeMiles.
People immediately configure their laptop to get up and coding…
The thing is, the speakers turn themselves into the “Client” (or the product owner, because XtremeMiles is a Scrum project) and the “Scrum Master”, and they ask us, the developers, to adopt a Test Driven Development procedure (we write the tests, with JUnits, before we code).
But the main aspect developed is that we’re organized in a Scrum project (it was actually the first time I experienced this kind of Agile organization).
So to sum up the procedure :
• First, we have a meeting with the Scrum master and the product Owner to ask questions (5mn), to agree on engagement (5mn for the team to choose the cards proposed by the product owner, which contain stories, tracing functionalities) and for the sprint backlog (5mn);
• Then, the sprint lasts 3 days for each iteration (a day in this game lasts 20 minutes, divided into 2 minutes of stand up meeting, where developers tell the Scrum Master what they’ve done, the problems they’ve encountered and what they’re going to achieve; and 18 minutes of work)
• Finally, it’s time to show the demo where the developers and the Scrum Master present to the client what they have achieved during the iteration

To code, we used eclipse with subclipse and JUnit, the speakers prepared a Bamboo (continuous integration) to test if a commit would break the build (we were under pressure !)

I attended this session 3 hours (2 iterations) and it was quite fun and very interesting : we’ve been able to witness problems of communication between teams, the way an agile project can rapidly react, etc…
This session was so popular, the organization decided to make it last one day more !

The afternoon, I was present at the “Sujets Eclairs” (lightening talks) session; where anyone in the room can present a subject and explain it in 10 minutes.(usually people who talk during lightening talks are not familiar with public presentations; moreover subjects presented are usually not prepared)
Many topics were proposed, most of them were about project management and agility.(which was nice actually)
The first day finished with some words from the sponsors, among them, Valtech, my employer ! (and also an excellent dinner !)