Sniffing for Array#to_s usage before upgrading to ruby 1.9 (where the behaviour changes)

method_sniffer.rb

# Log Array#to_s to make sure we are not using it and expeting the Ruby 1.8.x behaviour
class Array
  alias :_to_s :to_s

  def to_s(*args)
    Rails.logger.warn "Was calling Array#to_s from #{caller.first.split(":in").first}"
    _to_s(*args)
  end
end