Reek gem is a code smell detector for ruby. It examines Ruby classes, modules, methods and reports any code smells it finds.
To install this gem, use:
gem install reek
USAGE:
1/ Scan the current directory:
<pre>$ reek .</pre>
2/ scan specific directories like:
<pre>$ reek lib/your/files</pre>
To read more about reek gem click here(reek doc)
To find up to date details of what exactly reek will check in your code check this(reek wiki)