Reuse some methods make methods more verbose

I was doubting if instead of decreasing the quality in 2 steps, adding a parameter to the decrease_quality method and decrease it in 1 go was a better option.
I didnt go for it in the end as I like the verbosity at the moment and it's easier to follow later on why we decrease multiple times instead of e.g. decrease_quality(n) method

ruby/gilded_rose.rb

@@ -1,4 +1,6 @@
 class GildedRose
+  QUALITY_LOWER_LIMIT = 0
+  QUALITY_UPPER_LIMIT = 50
 
   def initialize(items)
     @items = items
@@ -11,6 +13,8 @@ class GildedRose
         update_aged_brie_quality(item)
       when 'Backstage passes to a TAFKAL80ETC concert'
         update_backstage_passes_quality(item)
+      when 'Conjured Mana Cake'
+        update_conjured_quality(item)
       when 'Sulfuras, Hand of Ragnaros'
         update_sulfuras_quality(item)
       else
@@ -20,31 +24,66 @@ class GildedRose
   end
 
   def update_aged_brie_quality(item)
-    item.sell_in -= 1
+    decrease_sell_in_day(item)
 
-    item.quality += 1
+    increase_item_quality(item)
-    item.quality += 1 if item.sell_in.negative?
+    increase_item_quality(item) if item.sell_in.negative?
-    item.quality = 50 if item.quality > 50
+
+    keep_quality_upper_limit_in_bounds(item)
   end
 
   def update_backstage_passes_quality(item)
-    item.sell_in -= 1
+    decrease_sell_in_day(item)
     return item.quality = 0 if item.sell_in.negative?
 
-    item.quality += 1
+    increase_item_quality(item)
-    item.quality += 1 if item.sell_in < 10
+    increase_item_quality(item) if item.sell_in < 10
-    item.quality += 1 if item.sell_in < 5
+    increase_item_quality(item) if item.sell_in < 5
-    item.quality = 50 if item.quality > 50
+
+    keep_quality_upper_limit_in_bounds(item)
+  end
+
+  def update_conjured_quality(item)
+    decrease_sell_in_day(item)
+
+    decrease_item_quality(item, 2)
+    decrease_item_quality(item, 2) if item.sell_in.negative?
+
+    keep_quality_lower_limit_in_bounds(item)
   end
 
   def update_normal_quality(item)
-    item.sell_in -= 1
+    decrease_sell_in_day(item)
-    item.quality -= 1
+
-    item.quality -= 1 if item.sell_in.negative?
+    decrease_item_quality(item)
-    item.quality = 0 if item.quality.negative?
+    decrease_item_quality(item) if item.sell_in.negative?
+
+    keep_quality_lower_limit_in_bounds(item)
   end
 
   def update_sulfuras_quality(item); end
+
+  private
+
+    def decrease_sell_in_day(item)
+      item.sell_in -= 1
+    end
+
+    def increase_item_quality(item)
+      item.quality += 1
+    end
+
+    def decrease_item_quality(item, by = 1)
+      item.quality -= by
+    end
+
+    def keep_quality_upper_limit_in_bounds(item)
+      item.quality = QUALITY_UPPER_LIMIT if item.quality > QUALITY_UPPER_LIMIT
+    end
+
+    def keep_quality_lower_limit_in_bounds(item)
+      item.quality = QUALITY_LOWER_LIMIT if item.quality < QUALITY_LOWER_LIMIT
+    end
 end
 
 class Item

ruby/specs/gilded_rose_spec.rb

@@ -220,7 +220,7 @@ describe GildedRose do
       end
     end
 
-    xcontext "when item name is 'Conjured Mana Cake'" do
+    context "when item name is 'Conjured Mana Cake'" do
       let(:item_name) { 'Conjured Mana Cake' }
 
       context 'when sell by date has not passed' do
@@ -245,7 +245,7 @@ describe GildedRose do
 
         it 'lowers sell_in by 1' do
           subject.update_quality
-          expect(items[0].sell_in).to eq 2
+          expect(items[0].sell_in).to eq 0
         end
       end
 

ruby/texttest_fixture.rb

@@ -12,8 +12,7 @@ items = [
   Item.new(name="Backstage passes to a TAFKAL80ETC concert", sell_in=15, quality=20),
   Item.new(name="Backstage passes to a TAFKAL80ETC concert", sell_in=10, quality=49),
   Item.new(name="Backstage passes to a TAFKAL80ETC concert", sell_in=5, quality=49),
-  # This Conjured item does not work properly yet
+  Item.new(name="Conjured Mana Cake", sell_in=3, quality=6),
-  Item.new(name="Conjured Mana Cake", sell_in=3, quality=6), # <-- :O
 ]
 
 days = 2