A timer for the "baby steps" exercise/technique for doing TDD. But actually, this is some really bad piece of "legacy" code that you can use for refactoring exercises.
Legacy Code Refactoring at Softwerkskammer Munich: This blog post describes some exercises I am doing with groups of people using this code.
Do you want me to facilitate this exercise at your conference / user group or meetup / your company? Contact me at [email protected]
I love to hear your feedback on Twitter or per email. And if you use this code as a Kata, for yourself or during a meetup, please tell me - I love to hear your experiences! Also, if you have any questions, please contact me:
[email protected]
@dtanzer
The C# version of the original code was humbly contributed by Paul Rohorzka (@paulroho).
Want to contribute a language or a new variant/twist to the existing code? Just open a pull request. Here are some characteristics of the original code that you may (or may not) want to preserve:
- Single Responsibility Violations Almost every part of the code violates the single responsibility principle (i.e. does more than one thing).
- High Coupling When you read or refactor the code, you'll see that almost every little bit of it depends on other, seemingly unrelated parts of the code (with different mechanisms).
- Low Cohesion Unrelated things happen close to each other in the code.
- Low Level Constructs The code does not "protect" itself from low level APIs. For example, it makes multiple calls to "System.currentTimeMillis" and uses threading constructs directly. This makes testing harder.
- Reasonable Names Things are mostly reasonably well named. I did not want to write unreadable code: I wanted to create code that is hard to change (because of its structure / interdependencies), even though it is fairly easy to understand.
- Complicated UI This code renders HTML within a Swing application. You usually would not do it exactly like that in a "real" Java application (But I have really seen HTML inside a JPane in a real project to render a small part of the UI). On the other hand, this adds some fun string manipulating code...
This is a little timer app you can use for the "Taking baby steps" TDD exercise: http://blog.adrianbolboaca.ro/2013/01/the-history-of-taking-baby-steps/
- You can move the timer window around with your mouse.
- Once you start the timer, the window stays always on top.
- When the timer counts down to zero, it becomes red because you did not take a baby step. Throw away everything you wrote in the two minutes before.
- When you finish your red/green/refactoring cycle before the timer counts down to zero, commit your changes and press "Reset" in the timer window.
I created this project for two reasons:
- To have a baby steps timer.
- To have some code for a refactoring screen cast (that was actually the real reason).
Because of the second reason, I started with pretty ugly code. I had two prototypes, one for playing the sounds and one for drawing the timer window.
I put them together in a class and added workaround after workaround, until the timer was working. I tried to make sure to make the code as hard to test as possible, while I still wanted it to be easy to understand.
But then I did not finish the screen cast, even though I started recording it. But I am still using this code to practice refactoring myself and to facilitate legacy code sessions at user group meetings and during trainings.
This project uses CC-Licensed sounds from freesound.org:
- Ships Bell by "acclivity" http://www.freesound.org/people/acclivity/sounds/32304/ http://www.freesound.org/people/acclivity/
- Bowl Struck by "suburban gorilla" http://www.freesound.org/people/suburban%20grilla/sounds/2166/ http://www.freesound.org/people/suburban%20grilla/
Copyright 2013 David Tanzer ([email protected], @dtanzer)
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
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