Ruby 2.x Array#to_set removed

[davidcoallier]

Description

Cistern's collection.rb uses to_set on BLACKLISTED_ARRAY_METHODS which is an Array.

However, in Ruby 2.x (http://www.ruby-doc.org/core-2.0/Array.html, http://www.ruby-doc.org/core-2.1.1/Array.html), the to_set method has been removed.

Expected Behaviour

Be able to use and run cistern in Ruby 2.x which is the default OSX version in Mavericks.

Actual Behaviour

Exception is thrown when using the collections:

/Library/Ruby/Gems/2.0.0/gems/cistern-0.5.3/lib/cistern/collection.rb:9:in `<class:Collection>': undefined method `to_set' for #<Array:0x007f8f4a3220b8> (NoMethodError)

How to reproduce

Instantiate a Collections object and invoke BLACKLISTED_ARRAY_METHODS

Possible Fix

Due to my restricted knowledge of Ruby and how to best include scripts, I could only test the fix with what I've been given :)

In collections.rb I've done the following:

require 'set'

class Cistern::Collection
  extend Cistern::Attributes::ClassMethods
  include Cistern::Attributes::InstanceMethods

  BLACKLISTED_ARRAY_METHODS = Set.new [
    :compact!, :flatten!, :reject!, :reverse!, :rotate!, :map!,
    :shuffle!, :slice!, :sort!, :sort_by!, :delete_if,
    :keep_if, :pop, :shift, :delete_at, :compact
  ] # :nodoc

This appears to fix the issue. Should I make a pull-request with this?

[lanej]

2.1.1 :001 > [].to_set
NoMethodError: undefined method `to_set' for []:Array
    from (irb):1
    from /Users/jlane/.rvm/rubies/ruby-2.1.1/bin/irb:11:in `<main>'
2.1.1 :002 > require 'set'
true
2.1.1 :003 > [].to_set
[]

i believe that one of the test dependencies has the side effect of requiring set.