Question

In Ruby/Rails, is there a “catch-all” rescue statement that also allows for more specific rescue possibilities? I tried

begin
  # something
rescue URI::InvalidURIError
  # do something
rescue SocketError
  # do something else
rescue 
  # do yet another thing
end

It turns out that even when there’s URI::InvalidURIError or SocketError, it goes into the last rescue (i.e. it executes do yet another thing.) I want it to do something, or do something else, respectively.

Answer 1

require 'uri'
require 'socket'

Errors = [URI::InvalidURIError, SocketError]
a = lambda { |e=nil|
             begin
               raise e unless e.nil? 
             rescue URI::InvalidURIError
               puts "alligator"
             rescue SocketError
               puts "crocodile"
             rescue
               puts "vulture"
             else
               puts "rhino"
             end }

Now try

a.( Errors[ 0 ] )
a.( Errors[ 1 ] )
a.call

It will behave exactly as you need. If your code above doesn’t work, then something else is going on in your program than you think.