Kata - Part 1: The gauntlet is thrown.

Kata are, according to Wikipedia, foundry of all knowledge (and often of factually correct knowledge) "the detailed choreographed patterns of movements practised either solo or in pairs".

In software circles, there's a similar concept, embodied by the practice of test-driven code exercises, often with the premise of a rather synthetic problem which the user (or pair) is left to solve in the strictest sense of TDD that she/he/they can muster. The point is to provide a problem which isn't necessarily new or tricky, leaving the body of the exercise to the players to practice their TDD cadence:

• Red: write one test and one test only, which tests a very specific requirement of the specification. Running all tests should give one "Red" result (one test fails, on purpose, for the intended reason).
• Green: implement the bare minimum code to get the last test to pass. Running all tests should give all "Green" results (all tests pass).
• Refactor: step in which the practitioner evaluates the code which was implemented to make the test pass and optionally renames, refactors or tidies up. If the code is deemed to be in a good state, the process is repeated.

Performing code katas provides the practitioner the opportunity to practice the strictest sense of TDD as well as examine programming, testing and style habits. The main idea is that the perfection which is sought during the kata will seep into production code. Some supplementary goals are to strengthen the practitioner's familiarity with her tools, hone her skills and encourage thought of alternative paths to the solution which still adhere to the TDD cadence. In addition, a kata can be used as a "jump-start" for the code "juices" as it were: an exercise where the output will be discarded (and hence isn't completely material), but where the practitioner's thought patterns can be aligned with the environment of programming towards a goal in preparation for production work.

At least, I've found it can be a good way to get the coding started.

I work at Chillisoft where one of the products in development at the moment is a kata assistant: Katarai. (Full disclosure: much of the gruesome innards of Katarai are the result of a fevered few tinkering sessions with a colleague, Mark Whitfield, so I kind of have a dog in this race, though I'm not part of the active development team for it).

Katarai aims to address a few issues with the code kata concept:

• Seasoned developers often can't wrap their heads around the concept of writing code you know you're about to throw away, or the concept of practicing TDD cadence simply for the practice. Katarai provides feedback of your progress through a kata as well as providing (in the future), feedback about your improvements / changes over time (and potentially a competitive flavour in that you could compare times or other metrics you derive from katas with those of your friends).
• Juniors may find it difficult to get into katas -- the code requirements can be a little esoteric and the TDD cadence hasn't taken hold yet.
• Code katas aren't necessarily fun by nature -- Katarai tries to change this perception a little.
• Katarai also times your attempts -- which leads us to where we are with this article. More on that later. 

(and probably others).

I gladly postulate the code katas are beneficial for programmers of any level. You could use them to familiarise yourself with a new language, you can use them just as part of the rhythm of your coding day, you can use them to keep your keyboard and tooling skills tip-top... Basically, you can use them for the same reasons martial artists do:  

"The basic goal of kata is to preserve and transmit proven techniques and to practice self-defence. By practicing in a repetitive manner the learner develops the ability to execute those techniques and movements in a natural, reflex-like manner."

Replace "self-defence" with "the skill you aim to master" and you can see how the concept applies to code (:

Recently, there was a challenge at work to complete the String Kata (yes, I really did just push you off to Google there -- there are too many great links to follow!) in under 17 minutes. The challenge isn't all that foreign to us: a few months back, a requirement was put forth that all developers should be able to complete the String Kata in 20 minutes or less to demonstrate proficiency in their programming environment. The original "20 minutes" requirement could be met in any language and environment of choice. The 17-minute challenge was done as part of internal testing for Katarai, so had to be in C#, using Visual Studio, though addons and extensions which facilitate production are also allowed.

I had already been testing out Katarai (that whole "dog in the race" thing), so I ran a quickie and submitted my time for the competition: 13:48. I thought that was a reasonable time; it was certainly well under the required 17 minutes and one of the fastest times I had recorded. I was quite pleased with myself.

It wasn't long until Peter Wiles replied to the mail thread to the effect that he had completed in 12:44.

The time was a challenge. The little smiley-face at the end of the email was just plain infuriating.

Read more in part 2