Почему делает этот метод для pluralizing названий категории не, работают во всех случаях?

PLURALIZATION_EXCEPTIONS = "hardware",'memory'
def pluralize_category_name(name)
  category = name.split(' and ')
  exceptions_to_exp = ""

  category.map! { |e| 
    if e.match(/^[A-Z]+$/)  and !e.match(/^[A-Z]+S$/)
      e = e.pluralize
    end
    (PLURALIZATION_EXCEPTIONS.include?(e.downcase)  || e.match(/^[A-Z]+S$/) ||
      e.match(/[memory|hardware]/) )? e : e.pluralize
  }.join(' and ')
end

Тест должен, и ожидание должно быть следующие:

it "properly pluralizes hardware as hardware" do
   pluralize_category_name("hardware").should == "hardware"
end

it "properly pluralizes UPS as UPS" do
   pluralize_category_name("UPS").should == "UPS"
end

it "properly pluralizes PDA and Portable Hardware as PDAs and Portable Hardware" do
   pluralize_category_name("PDA and Portable Hardware").should == "PDAs and Portable Hardware"
end

it "properly pluralizes perfume and cologne as perfumes and colognes" do
   pluralize_category_name("perfume and cologne").should == "perfumes and colognes"
end

Последние тестовые сбои :(

На помощь!