rspec/rspec-core — pull request #604 by eregon (2012-04-20 18:37:38+00:00)
Title: raise an ArgumentError when the arity of a Proc filter is wrong

Hello,

Following #556, here is the rebased version on master.

It ensures a Proc with an arity different of 1 and 2 is handled correctly (raise an error, or yield successfully).
It also allows Proc with 0 arguments, which do not use the metadata value (i.e.: depending only on external factors).