"How often have you thrown up your hands in disgust at the poor
quality of documentation for an open source project? Wouldn't it be
nice if someone put together a documentation coverage tool that
worked like test coverage too ls? Well, youâ€™re
in luck--dcov is here (at least for Ruby code).
"dcov is still pretty immature (the current release is called
'Young and Feeble'), but it's showing a lot of promise. It's
already capable of verifying that each module, class, and method of
your code is documented. The upcoming release adds coverage
checking for each parameter to a method..."