Coverity Code Analysis and Ruby

Recently, Coverity added Ruby to it's list of scanned projects (overview data is available here). Because Perl and Python were already in Coverity's target list, this allows us to look at a code quality comparison between these three languages. Below, I've listed each langage with its Lines of Code (LoC), current number of defects, original number of defects, current rate of defects per KLoC, and the original rate of defects per KLoC. I've had to calculate the last figure since it's not explicitly available on Coverity's wesite.

Lang	LoC	cur defects	defect rate
Perl	485,001	67	0.138
Python	273,980	14	0.051
Ruby	258,908	30	0.116

Python looks very good here, probably because they've been aggressive about attacking the reported defects. In the grand scheme of things though, All three languages look pretty good.

Lang	LoC	orig defects	defect rate
Perl	485,001	89	0.185
Python	273980	96	0.350
Ruby	258,908	30	0.116

This is where Ruby shows a bit better than the 'competition'. Ruby has a pretty good (low) defect rate before we've even gotten any feedback from Coverity. Hopefully we can be at least as aggressive about attacking our defects as the Python community. In fact, there's an even better target — AMANDA:

Lang	LoC	cur defects	defect rate
AMANDA	0	88,414	0.000

(By the way, they started out with a rate of 1.227)