jiren/filter.js — pull request #1 by prawin (2011-11-05 07:40:41+00:00)
Title: Check if eval_out is null

I was trying out filter.js with a rails application. Added test filter on `login_count` of `users`.
`eval` returns `null` for users never logged in yet i.e. for `login_count => nil`.
This caused error on `eval_out.constructor`