refactored code using classes for readability + conjured handler

python/gilded_rose.py

@@ -1,4 +1,11 @@
 # -*- coding: utf-8 -*-
+from item_handler import (
+    AgedBrieHandler,
+    BackstagePassesHandler,
+    DefaultItemHandler,
+    SulfurasHandler,
+    ConjuredItemHandler)
+
 
 class GildedRose(object):
 
@@ -7,42 +14,24 @@ class GildedRose(object):
         self.AGED_BRIE = "Aged Brie"
         self.SULFURAS = "Sulfuras, Hand of Ragnaros"
         self.BACKSTAGE_PASSES = "Backstage passes to a TAFKAL80ETC concert"
+        self.CONJURED = "Conjured Mana Cake"
 
     def update_quality(self):
         for item in self.items:
-            self.update_each_item_quality(item)
+            self.__update_each_item_quality(item)
             # print(f'Log: {item}\n')
 
-    def update_each_item_quality(self, item):
-        # Update item.sell_in
-        if item.name != self.SULFURAS:
-            item.sell_in = item.sell_in - 1
-        # Update item.quality
-        if item.name != self.AGED_BRIE and item.name != self.BACKSTAGE_PASSES:
-            if item.quality > 0:
-                if item.name != self.SULFURAS:
-                    item.quality = item.quality - 1
-        else:
-            if item.quality < 50:
-                item.quality = item.quality + 1
-                if item.name == self.BACKSTAGE_PASSES:
-                    if item.sell_in < 10:
-                        if item.quality < 50:
-                            item.quality = item.quality + 1
-                    if item.sell_in < 5:
-                        if item.quality < 50:
-                            item.quality = item.quality + 1
-        if item.sell_in < 0:
-            if item.name != self.AGED_BRIE:
-                if item.name != self.BACKSTAGE_PASSES:
-                    if item.quality > 0:
-                        if item.name != self.SULFURAS:
-                            item.quality = item.quality - 1
-                else:
-                    item.quality = item.quality - item.quality
-            else:
-                if item.quality < 50:
-                    item.quality = item.quality + 1
+    def __update_each_item_quality(self, item):
+        ITEM_SWITCH = {
+            self.AGED_BRIE: AgedBrieHandler(),
+            self.SULFURAS: SulfurasHandler(),
+            self.BACKSTAGE_PASSES: BackstagePassesHandler(),
+            self.CONJURED: ConjuredItemHandler()
+        }
+        item.handler = ITEM_SWITCH.get(item.name, DefaultItemHandler())
+
+        item.handler.update_sell_in(item)
+        item.handler.update_quality(item)
 
 
 class Item:

python/item_handler.py

@@ -0,0 +1,44 @@
+
+class DefaultItemHandler(object):
+    def _decrease_item_quality(self, item, amount: int = 1):
+        item.quality = max(0, item.quality - amount)
+
+    def _increase_item_quality(self, item, amount: int = 1):
+        item.quality = min(50, item.quality + amount)
+
+    def update_quality(self, item):
+        self._decrease_item_quality(item)
+        if item.sell_in < 0:
+            self._decrease_item_quality(item)
+
+    def update_sell_in(self, item):
+        item.sell_in = item.sell_in - 1
+
+class AgedBrieHandler(DefaultItemHandler):
+    def update_quality(self, item):
+        self._increase_item_quality(item)
+        if item.sell_in < 0:
+            self._increase_item_quality(item)
+
+class BackstagePassesHandler(DefaultItemHandler):
+    def update_quality(self, item):
+        self._increase_item_quality(item)
+        if item.sell_in < 10:
+            self._increase_item_quality(item)
+        if item.sell_in < 5:
+            self._increase_item_quality(item)
+        if item.sell_in < 0:
+            item.quality = 0
+
+class SulfurasHandler(DefaultItemHandler):
+    def update_quality(self, item):
+        pass
+
+    def update_sell_in(self, item):
+        pass
+
+class ConjuredItemHandler(DefaultItemHandler):
+    def update_quality(self, item):
+        self._decrease_item_quality(item, 2)
+        if item.sell_in < 0:
+            self._decrease_item_quality(item, 2)

python/tests/test_backstage_pass.py

@@ -1,11 +1,5 @@
 from gilded_rose import Item, GildedRose
 
-'''
-"Backstage passes", like aged brie, increases in Quality as its SellIn value approaches;
-Quality increases by 2 when there are 10 days or less and by 3 when there are 5 days or less but
-Quality drops to 0 after the concert
-'''
-
 BACKSTAGE_PASSES = "Backstage passes to a TAFKAL80ETC concert"
 
 # Backstage passes, increases in Quality as its SellIn value approaches

python/tests/test_conjured.py

@@ -0,0 +1,9 @@
+from gilded_rose import Item, GildedRose
+CONJURED = "Conjured Mana Cake"
+
+# "Conjured" items degrade in Quality twice as fast as normal items
+def test_conjured_item_degrades_twice():
+    items = [Item(CONJURED, 1, 12)]
+    gilded_rose = GildedRose(items)
+    gilded_rose.update_quality()
+    assert items[0].quality == 10