The Shout Kata: Programming a Client-Server infrastructure in full TDD

Emmanuel Gaillot (Octo Technology)

Tutorials · Developing

Monday, 14:00, 3 hours 30 minutes | Meeting Room 5

TDD does wonders for coders. The technique in itself is outrageously simple to grasp. It's easy to demonstrate it in a couple of hours. Many books and tutorials have been written on the subject, yet it's still not enough. Some notoriously hard-to-test cases have yet to be properly addressed.
Building a client-server infrastructure is one of them. Most of the available documentation on constructing a client-server system involves multithreading... and code snippets with no test. Indeed: because of its lack of determinacy, multithreaded code is a test nightmare.

What to do? Copying and pasting code snippets in blind faith, hoping they won't break later? Making ("it's okay once in a while!") an exception to the TDD discipline?

We don't have to. There is a better option.

In this session we will program from scratch a full-fledged client-server system providing a simple broadcast service (in the spirit of the "shout" command available in text-based virtual worlds), in full TDD. All in one thread.

This coding journey will happen in the form of a (Paris Coders' Dojo) kata session in Ruby, a session during which the developer and the copilot write the full code directly in front of – and with the full collaboration of – the audience, submitting their design to everybody's questions, comments, suggestions and approbation.

Emmanuel Gaillot is a software engineer and an experienced designer for theatre and dance. He has adapted XP practices and principles for the theatre, and he currently works on instilling performance art practices back into the field of software making. He is a founding member of the Coders' Dojo in Paris. He has presented the Dojo and its works at various past conferences. He works in Paris, France, for Octo Technology as an XP coach.