My attempt at implementing the auction sniper example from part II of Growing Object-Oriented Software, Guided By Tests. I've tagged the repository at the end of each chapter:
- Chapter 10
- Chapter 11
- Chapter 12
- Chapter 13
- Chapter 14
- Chapter 15
- Chapter 16
- Chapter 17
- Chapter 18
- Chapter 19
There are links to a few other people's implementations on the GOOS site, including another one in Ruby from Brian Marick.
Tested using the version in .ruby-version. I started in 1.9.3 then switched
to 2.0.0, but as far as I know anything 1.9 or above ought to work.
The Vines XMPP server is started and stopped automatically by the tests.
For the client I tried xmpp4r and xmp4r-simple, but couldn't get either of them to work properly, so ended up with Blather. This runs in EventMachine so has to be started in its own thread to avoid blocking the rest of the application.
I considered using Swing to keep close to the book, but that would have restricted the app to only running on JRuby. I tried Tk and Qt, but couldn't figure out any easy way of testing them, and they didn't seem to take particularly well to being run in separate threads.
In the end, I settled on GTK+. The default Mac version runs in X Windows and is fairly ugly, but it exposes all its widgets cleanly so I can poke them and assert things about them from the end-to-end tests.
I'm using Cucumber for end-to-end/acceptance tests, and RSpec (version 2.14.0rc1, so I can use spies) for unit tests.
To test the UI, I'm just calling methods directly on the main Gtk::Window object (which still runs as normal and can be seen on the screen as the tests run).
I'm trying to stick pretty closely to the design used in the book. However, the book makes heavy use of Java interfaces, which don't exist in Ruby. As a compromise between explicit interfaces and pure duck-typing, I've created specs for the interfaces, which simply check that anything acting as that role implements the correct methods.
Unlike Smack, Blather works at the individual message level, rather than modelling persistent chats. To ensure messages only get sent to the appropriate listener for each auction, I've added a guard on the message originator when registering the listener.
RSpec doesn't have the "states" feature from JMock, but it's easy enough to replicate by executing a block when the stubbed methods are called, and setting or checking an instance variable as appropriate.
There are no enums in Ruby, so classes like Column and SniperState are
implemented as (rather inelegant) collections of constants.
There seems to be a race condition on startup – every so often a feature will fail because (I think) the auction server never receives a join request from the sniper.