I was recently discovering the results of the CMD tool in the travis-ci test plant.
Some benefits are obvious, as some violation rules directly address missing variables, or mistyped variables, unused globals.
I'm more doubting about the settings of cyclomatic and function length settings.
Obviously, if you just design a very simple plugins with less then 10 files, you may not address such heavy algorithms that would need to pass the limits. Theoretical good practices would indeed pray for short functions, low number of public functions in class. that is obviously theoretic. In big plugins, promoting such good practices lead to a practical impossibility : multiply the number of function and number of small classes and you'll get an awfull to track and debug hyper-granular construct. We know one example of such implementation as Zend framework that we all know it is quickly unpenetrable.
Being validating around 120 plugins of all sizes (from a small quickaccess rule to an around 100k lines integrated shop, very few of them (none in reality) would comply with the cyclomatic and complexity violations.
So would'nt it be wise to soften the rules on those measurement ?