October 8th – #xpman 64 – A Practical With Ups and Downs: The Mind-bending Lift Kata

This month we will be doing a practical session so bring a laptop. There will be people around (or in the pub from 6.30pm and we will be starting at 7pm. Get a ticket here so we know roughly how many to expect.

The lift kata sounds simple: “a lift responds to calls containing a source floor and direction, and delivers passengers to requested floors” (http://blog.milesburton.com/2013/03/28/elevator-kata-mind-bending-pairing-exercise/). But it doesn’t take long before you find yourself asking many questions:

* How do you model the fact that events need to happen in a particular order?

* Should you start with one lift or several?

* Can the lifts be independent operators, or do you need some kind of over-arching lift manager?

* Can you write the tests without introducing some kind of time / scheduling element?

* Should lift efficiency be measured with respect to average client wait time, or how much energy is used?

* Should the lifts be the old-fashioned kind that don’t know which floor you’re visiting until you enter the lift, or should users be given control panels into which they can enter their destination floor?

It can keep you busy for hours at a time, but in this exercise we will focus on just one or two key concepts. Hopefully people will be inspired to take it away with them and keep working on it – then we can all compare notes.

This kata will be delivered by @ClareSudbery, who has been working on this kata sporadically for the last few weeks, and has written a blog post about it here: http://engineering.laterooms.com/making-tests-readable/