This is the only one I could find, haven't tried it yet, but it seems
promising, if a bit young:
Metric_fu includes roodi - it's a decent place to start.
> I have been looking around for something like checkstyle (Java code
> review tool) for ruby.
I've personally found that (as Ryan suggested) the best "review" is a
human reading the code. This is easier in Ruby than in Java, since
there's considerably less visual noise in a well-written block of
The metric_fu tools do identify several of the remaining issues (code
duplication, excessive cyclomatic complexity,etc) but aren't really
intended to be used proscriptively (in other words, making a hard rule
"no complexity ratings over 5 EVAR!" will lead to problems) but rather
as a roadmap for detailed human review.