gistfile1.ru

# Finds all setter methods for the object, 
# builds a new object with these methods set to an arbitrary value, 
# checks if the given attrs are able to be mass assigned and all others are not,
# and finally returns true if there are no failures.
#
# (modified from: http://chrisconley.posterous.com/using-rspec-to-test-attraccessible)
Spec::Matchers.define :only_mass_assign_accessible_attributes do |*attrs|
  match do |object|
    @attrs = attrs
    setters = object.methods.map{|m| m if m.match(/[a-z].*\=$/)}.compact
    getters = setters.map{|s| s.gsub('=', '').to_sym}

    accessible = object.class.accessible_attributes || []

    @shouldnt, @should, @found = [], [], []
    getters.each do |getter|
      g = getter.to_s
      if accessible.include?(g)
        if attrs.include?(getter)
          @should << g
        else
          @shouldnt << g
        end
      
        @found << getter
      end
    end

    @shouldnt.length == 0 && @found.length == @attrs.length
  end

  failure_message_for_should do |actual|
    str = ""
    str += "The accessible attributes did not match. Expected #{@attrs.to_yaml} but got #{@found.to_yaml}"
    str
  end
end