Update ItemFactory to use the new SpecialItem classes

ruby/lib/gilded_rose/item_factory.rb

@@ -1,12 +1,16 @@
 module GildedRose
   class ItemFactory
-    SPECIAL_ITEMS = ["Aged Brie", "Backstage passes to a TAFKAL80ETC concert", "Sulfuras, Hand of Ragnaros"]
+    SPECIAL_ITEM_KLASSES = {
+      "Aged Brie" => AgedBrieItem,
+      "Backstage passes to a TAFKAL80ETC concert" => BackstagePassesItem,
+      "Sulfuras, Hand of Ragnaros" => SulfurasItem,
+    }
+
+    GENERIC_ITEM_KLASS = GenericItem
+
     def self.create_item(name:, sell_in:, quality:)
-      if SPECIAL_ITEMS.include?(name)
-        return Item.new(name, sell_in, quality)
-      end
-  
-      GenericItem.new(name, sell_in, quality)
+      klass = SPECIAL_ITEM_KLASSES.fetch(name, GENERIC_ITEM_KLASS)
+      klass.new(name, sell_in, quality)
     end
   end
 end

ruby/tests/gilded_rose/item_factory_tests.rb

@@ -5,14 +5,22 @@ module GildedRose
   class ItemFactoryTests < Test::Unit::TestCase
     test ".create_item returns GenericItem instance if it is not a special item" do
       created_item = ItemFactory.create_item(name: "random_item", sell_in: 0, quality: 0)
-  
       assert_instance_of GenericItem, created_item
     end
-  
-    test ".create_item returns Item instance if Aged Brie item if given" do
+
+    test ".create_item returns AgedBrieItem instance if Aged Brie item is given" do
       created_item = ItemFactory.create_item(name: "Aged Brie", sell_in: 0, quality: 0)
-  
-      assert_instance_of Item, created_item
+      assert_instance_of AgedBrieItem, created_item
+    end
+
+    test ".create_item returns BackstagePassesItem instance if Backstage passes to a TAFKAL80ETC concert item is given" do
+      created_item = ItemFactory.create_item(name: "Backstage passes to a TAFKAL80ETC concert", sell_in: 0, quality: 0)
+      assert_instance_of BackstagePassesItem, created_item
+    end
+
+    test ".create_item returns SulfurasItem instance if Sulfuras, Hand of Ragnaros item is given" do
+      created_item = ItemFactory.create_item(name: "Sulfuras, Hand of Ragnaros", sell_in: 0, quality: 0)
+      assert_instance_of SulfurasItem, created_item
     end
   end
 end