For the past 5 months I’ve been involved in JRuby project, since it’s a perfect match for my interests: great object oriented scripting language on top of powerful Java platform. And so far, I’m enjoying every second of my time with JRuby! So I thought that I might just post this entry and describe how to contribute to JRuby effectively and comfortably, based on experience and what worked for me.

First major rule: Don’t be shy and submit the bug reports. It’s straightforward, just go to the Jira page for JRuby, get the account and follow the “Create a new issue in project JRuby” wizard. Sure, some bugs would have better chances to be accepted and fixed than others. Clear, precise description on what’s going on, with specified environment (which OS, which JRuby version) is always a plus. Short, reproducible test case attached to the bug would be great! Having a patch that fixes the bug is just perfect. History shows that bugs with test cases and with patches are being resolved much faster, which is not a surprise.

Second rule: Talk to core developers in case when you have some problems/issues with JRuby, or even if you just have some questions. And the best way to do that is to hang out on IRC channel #JRuby (more info here). This is probably the most useful way to be involved, since the core developers and many active JRuby users are always there, 24 hours a day. That heavy use of IRC was kind of unexpected for me, I was assuming that most of communication happens over email and thought that IRC is an outdated way to communicate. And I was very wrong. Now, I can’t even imagine how some other open source projects get away without using IRC. Seriously, IRC is the way. But there are also mailing lists if you insist, they are just being used less actively.

Third rule: Get the sources and start hacking. The sources are under Subversion, but many been using git-svn successfully as well. To build JRuby is very easy, just invoke ant, and that’s it. Everything that’s needed for the build is already in the repository, and there is no need to download any 3rd party dependencies. All you really need is the JDK and Ant installed. Once you have the fix, there are couple of ways to test it, to run unit tests via “ant test” and to run “rubyspecs” via “ant spec”. Also, most of the changes should be accompanied by the new unit tests that verify/validate the new behavior.

Probably the easiest way to find stuff to work on is to follow “rubyspecs” and try to make JRuby pass those spec tests that currently fail. The rubyspecs is a set of conformance/compatibility tests currently maintained as part of Rubinius project (to be extracted into stand alone project sooner or later). I’ll probably post more about rubyspecs in the future since for me this is an incredibly important piece of overall Ruby compatibility story. Currently, you can easily see which rubyspec tests are failing with JRuby and hence are excluded, just invoke “ant spec-show-excludes”.

Another great way to help out not only JRuby but other Ruby implementations is to start writing new rubyspecs. The Rubinius folks are very open about that and after few good submissions would probably offer the commit rights.

This entry was posted on Thursday, March 27th, 2008 at 8:51 am and is filed under JRuby. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.