Thinking Inside a Bigger Box

Do you know how to apply coding practices the technology stack that you use on a daily basis? Do you know how the technology stack works? For many programmers, it’s easy enough to use test-driven development with a trivial example, but it can be very hard to know how to apply it to the problems you face every day in your job.

Java web+database applications are usually filled to the brim with technologies. Many of these are hard to test and many of these may not add value. In order to explore TDD and Java applications, I practiced the Java EE Spike Kata in 2010. Here’s a video of me and Anders Karlsen doing this kata at JavaZone 2010.

A similar approach is likely useful for programmers using any technology. Therefore, I give you: The rules of the Architecture Spike Kata.

The problem

Create a web application that lets users register a Person with names and search for people. The Person objects should be saved in a data store that is similar to the technology you use daily (probably a relational database). The goal is to get a spike working as quickly as possible, so in the first iteration, the Person entity should probably only contain one field. You can add more fields and refactor the application later.

The rules

The most important rules are Robert Martin‘s three rules of Test-driven development:

• No code without test (that is, the code should never do something that isn’t required in order to get a test to pass)
• Only enough test to get to red (that is, the tests should run, give an error message and that error message should correct)
• Only enough code to get to green (that is, the tests should run and not give an error)
• (My addition: Refactor on green without adding functionality)

Secondly, application should be driven from the outside in. That is, your first test should be a top-level acceptance test that tests through http and html. It’s okay to comment out or @Ignore this test after it has run red for the first time.

Lastly, you should not introduce any technology before the pain of not doing so is blinding. The first time you do the kata in a language, don’t use a web framework beyond the language minimum (in Java, this means Servlets, in node.js it’s require('http'), in Ruby it means Rack). Don’t use a Object-Relational Mapping framework. Don’t use a dependency injection framework. Most definitely don’t use an application generator like Rails scaffold, Spring Roo or Lift. These frameworks can be real time savers, but this kata is about understanding how the underlying technology works.

As a second iteration, use the technologies you use on a daily basis, but this time set up from scratch. For example, if your project uses Hibernate, try configuring the session factory by hand. By using frameworks in simplest way possible, you’ll both learn more about what they bring to the table and how to use them properly. For complex technology like Hibernate, there’s no substitute for deeper understanding.

What to expect

So far, I’ve only done the Architecture Spike Kata in Java. But on the other hand, I’ve done it around 50 times together with more than ten other developers. I’ve written about how to get started with the Java EE Spike Kata (in Norwegian) on my blog before.

This is what I’ve learned about working with web applications in Java:

• Most Java web frameworks seem to harm more than they help
• Hibernate is a bitch to set up, but once it’s working, it saves a lot of hassle
• Using TDD with Hibernate helped me understand how to use Hibernate more effectively
• I’ve stopped using dependency injection frameworks (but kept on using dependency injection as a pattern)
• I have learned several ways to test web applications and database access independently and integrated
• I no longer have to expend mental energy to write tests for full stack application

The first time I write this kata with another developer, it takes around 3 to 5 hours, depending on the experience level of my pair. After running through it a few times, most developers can complete the task in less than an hour.

We get better through practice, and the Architecture Spike Kata is a way to practice TDD with the technologies that you use daily and get a better understanding of what’s going on.

I recently attended the XP Days Ukraine conference in a rainy, but beautiful and Christmas-decorated Kiev. I conducted a coding dojo and gave a talk where I demonstrated pair programming live together with Dima Mindra. After the talk, I got a few questions about how to run a Coding Dojo.

This article is meant as a guide to anyone wanting to start up a Coding Dojo, whether it’s in Kiev (Mikail/Aleksey), in Odessa (I’m looking at you, Dima!) or anywhere else in the world.

A Coding Dojo is a place to learn and have fun while programming

Quite simply, a Dojo is a gathering of programmers who come together to have fun and learn while programming. It’s always hands-on and it’s always social. In Oslo there are about 300 people who have signed up their interest. We meet on average once per month, usually in a bar. There is anywhere from 5 to 25 people who attend any given meeting.

Alternatively, a Coding Dojo can be used to describe a single event for a company or team that wants to train their developers in a hands-on and engaging way.

Coding Dojo Style #1: Many programmers, one problem

In the martial art Aikido, “Randori” means that multiple people are attacking the same person. In the Coding Dojo, “Randori” means that multiple programmers are attacking the same problem.

In order to organize a randori-style dojo, you need a computer with a development environment, a projector, a place to meet, a facilitator and 4-10 programmers who attend. Here is one way to carry out a Randori Style Coding Dojo:

• If the group is new to test-driven development, the facilitator demonstrates the red-green-refactor cycle with a simple example (no more than 10 minutes)
• The facilitator introduces the programming problem (kata) to solve. The Prime Factors kata is a good first kata for a group
• The faciliator invites a partner to join him at the keyboard. The facilitator writes a first test, makes sure it runs red and invites someone else from the group to take his place.
• Each pair works on the problem for 5-10 minutes, the facilitator then makes sure that one person in the pair is switched out with someone in the audience.
• After about 45-60 minutes of working on the problem, call a break and review what’s happened. Personally, I’ve had success with asking everyone to name one thing that they learned, one thing that surprised them, and one thing they want to change about the way they work.
• After the review, the group can work on another kata (problem), try the same problem again or use another exercise form

The biggest barrier for most people to participate in a Coding Dojo is that most programmers have never programmed live in front of anyone else. This feels extremely awkward and vulnerable at first. As a facilitator, your most important job is to help everyone feel at ease at whatever level they are.

Coding Dojo Style #2: Pairs working in parallel

Some people report that a Randori-style dojo can feel slow and constrained. As an alternative, I sometimes use the CyberDojo software, created by Jon Jagger. For a CyberDojo style dojo, you need a place to meet, a computer with a projector and internet access, a facilitator and 6-30 programmers with their own laptops with a web-browser and internet access. Here is how I usually carry out a CyberDojo style Coding Dojo:

• The group forms pairs of programmers
• The facilitator sets up a CyberDojo on http://cyber-dojo.com. (It may be smart to send a quick tweet to Jon to make sure he’s not planning to restart the server at this time)
• All the pairs work in the fashion the group has agreed to work for 30-60 minutes
• After the coding session, the facilitator uses the CyberDojo dashboard as a focus for discussions of programming habits

If you’re thinking about facilitating a Cyber Dojo, just go to http://cyber-dojo.com, try creating a dojo and solve a kata. You can do this on your own now!

Coding Dojo Style #3: Working under stress

Extreme startup is a workshop based around a server that will ask questions of the software running on the computer of each participating pair. As the pairs answer questions correctly, they are awarded points. I usually run an Extreme Startup session after having run a strict TDD Coding Dojo. In the Extreme Startup, teams can work any way they want.

The Extreme Startup software is developed by Matt Wynne and Richard Chatley. There are several forks, including mine, which tries to maximize the stress.

In order to run an Extreme Startup workshop, you need a place to meet, a computer with a projector and the Extreme Startup software, a facilitator and 6-30 programmers with their own laptops with a development environment of their choice. All the computers need to be on a shared network so they can communicate using TCP/IP.

• The group form pairs. If someone wants to work solo, or in bigger groups, that is okay, too
• The facilitator starts the Extreme Startup software in warmup mode
• The facilitator demonstrates how to get started (I use this collection of starting points in a number of languages)
• The teams work for around 30 minutes until (almost) everybody have been able to get a web server running and registered on their computer
• The facilitator starts the Extreme Startup software in real mode
• All the teams reregister their servers. All hell breaks lose as they try to implement the questions as fast as they can
• After the teams have worked for another 60 minutes, the facilitator breaks off the competition. Ask the teams on the top to describe how they worked

If you’re thinking about facilitating an Extreme startup, download my or Richard Chatley’s version of the software to your computer. The README file explains how to get it running. Then download Bodil Stokke’s collection of starting point to your computer. Use the ruby/sinatra_for_dummies starting point to create a solution. Let me know of your experiences when trying out the software, so I can improve the README.

You can do this by yourself now!

Start a coding dojo

A coding dojo is a great way to build your professional network, become a better programmer, and to have fun! I hope this article can help you get started.