Question

following a RoR security tutorial (here), i wrote something along the lines of

@@private_re = //
def secure?
  action_name =~ @@private_re
end

the idea is that in the base case, this shouldn’t match anything, and return nil. problem is that it doesn’t. i’ve worked around for the time being by using a nonsensical string, but i’d like to know the answer.

Answer 1

The empty regular expression successfully matches every string.

Examples of regular expressions that will always fail to match:

• /(?=a)b/
• /\Zx\A/
• /[^\s\S]/