Added factory pattern to handle this and also test case for conjured item

python/factory_item.py

@@ -0,0 +1,15 @@
+from python.item import AgedBrie, Sulfuras, Backstage, Conjured, RegularItem
+
+item_to_class_map = {
+    "Aged Brie": AgedBrie,
+    "Sulfuras, Hand of Ragnaros": Sulfuras,
+    "Backstage passes to a TAFKAL80ETC concert": Backstage,
+    "Conjured": Conjured
+}
+
+
+class FactoryItem:
+
+    @staticmethod
+    def create_new_item(name, sell_in, quality):
+        return item_to_class_map.get(name, RegularItem)(name, sell_in, quality)

python/gilded_rose.py

@@ -1,19 +1,5 @@
 # -*- coding: utf-8 -*-
 
-def decrease_quality(item, decrease_quality_by=None):
-    if not decrease_quality_by:
-        if item.sell_in <= 0:
-            decrease_quality_by = 2
-        else:
-            decrease_quality_by = 1
-
-    item.quality = max(item.quality - decrease_quality_by, 0)
-
-
-def increase_quality(item, increase_quality_by=1):
-    item.quality = min(item.quality + increase_quality_by, 50)
-
-
 class GildedRose(object):
 
     def __init__(self, items):
@@ -21,30 +7,4 @@ class GildedRose(object):
 
     def update_quality(self):
         for item in self.items:
-            if item.name == "Sulfuras, Hand of Ragnaros":
+            item.update_quality()
-                continue
-            elif item.name == "Aged Brie":
-                increase_quality(item)
-            elif item.name == "Backstage passes to a TAFKAL80ETC concert":
-                if item.sell_in <= 0:
-                    item.quality = 0
-                elif item.sell_in <= 5:
-                    increase_quality(item, 3)
-                elif item.sell_in <= 10:
-                    increase_quality(item, 2)
-                else:
-                    increase_quality(item)
-            else:
-                decrease_quality(item)
-
-            item.sell_in = item.sell_in - 1
-
-
-class Item:
-    def __init__(self, name, sell_in, quality):
-        self.name = name
-        self.sell_in = sell_in
-        self.quality = quality
-
-    def __repr__(self):
-        return "%s, %s, %s" % (self.name, self.sell_in, self.quality)

python/helper.py

@@ -0,0 +1,12 @@
+def decrease_quality(quality, sell_in, decrease_quality_by=None) -> int:
+    if not decrease_quality_by:
+        if sell_in <= 0:
+            decrease_quality_by = 2
+        else:
+            decrease_quality_by = 1
+
+    return max(quality - decrease_quality_by, 0)
+
+
+def increase_quality(quality, increase_quality_by=1) -> int:
+    return min(quality + increase_quality_by, 50)

python/item.py

@@ -0,0 +1,58 @@
+from python.helper import decrease_quality, increase_quality
+
+
+class Item:
+    def __init__(self, name, sell_in, quality):
+        self.name = name
+        self.sell_in = sell_in
+        self.quality = quality
+
+    def update_quality(self):
+        """Update the quality of an item"""
+        pass
+
+    def __repr__(self):
+        return "%s, %s, %s" % (self.name, self.sell_in, self.quality)
+
+
+class RegularItem(Item):
+
+    def update_quality(self):
+        """Update the quality of an item"""
+        self.quality = decrease_quality(quality=self.quality, sell_in=self.sell_in)
+        self.sell_in = self.sell_in - 1
+
+
+class Sulfuras(Item):
+
+    def update_quality(self):
+        pass
+
+
+class Backstage(Item):
+
+    def update_quality(self):
+        if self.sell_in <= 0:
+            self.quality = 0
+        elif self.sell_in <= 5:
+            self.quality = increase_quality(quality=self.quality, increase_quality_by=3)
+        elif self.sell_in <= 10:
+            self.quality = increase_quality(quality=self.quality, increase_quality_by=2)
+        else:
+            self.quality = increase_quality(quality=self.quality)
+
+        self.sell_in = self.sell_in - 1
+
+
+class AgedBrie(Item):
+
+    def update_quality(self):
+        self.quality = increase_quality(quality=self.quality)
+        self.sell_in = self.sell_in - 1
+
+
+class Conjured(Item):
+
+    def update_quality(self):
+        self.quality = decrease_quality(quality=self.quality, sell_in=self.sell_in, decrease_quality_by=2)
+        self.sell_in = self.sell_in - 1

python/test_gilded_rose.py

@@ -1,18 +1,19 @@
 # -*- coding: utf-8 -*-
 import unittest
 
-from gilded_rose import Item, GildedRose
+from gilded_rose import GildedRose
+from python.factory_item import FactoryItem
 
 
 class GildedRoseTest(unittest.TestCase):
     def test_normal_item_quality(self):
-        item = Item(name="foo", sell_in=5, quality=5)
+        item = FactoryItem.create_new_item(name="foo", sell_in=5, quality=5)
         gilded_rose = GildedRose([item])
         gilded_rose.update_quality()
         self.assertEqual(4, item.quality)
 
     def test_normal_item_quality_when_quality_is_zero(self):
-        item = Item(name="foo", sell_in=0, quality=0)
+        item = FactoryItem.create_new_item(name="foo", sell_in=0, quality=0)
         gilded_rose = GildedRose([item])
         gilded_rose.update_quality()
 
@@ -20,7 +21,7 @@ class GildedRoseTest(unittest.TestCase):
         self.assertEqual(0, item.quality)
 
     def test_normal_item_quality_if_sell_in_is_0(self):
-        item = Item(name="foo", sell_in=0, quality=4)
+        item = FactoryItem.create_new_item(name="foo", sell_in=0, quality=4)
         gilded_rose = GildedRose([item])
         gilded_rose.update_quality()
 
@@ -28,7 +29,7 @@ class GildedRoseTest(unittest.TestCase):
         self.assertEqual(2, item.quality)
 
     def test_aged_brie_quality_exceeded(self):
-        item = Item(name="Aged Brie", sell_in=0, quality=50)
+        item = FactoryItem.create_new_item(name="Aged Brie", sell_in=0, quality=50)
         gilded_rose = GildedRose([item])
         gilded_rose.update_quality()
 
@@ -36,13 +37,13 @@ class GildedRoseTest(unittest.TestCase):
         self.assertEqual(50, item.quality)
 
     def test_aged_brie_sell_in(self):
-        item = Item(name="Aged Brie", sell_in=10, quality=2)
+        item = FactoryItem.create_new_item(name="Aged Brie", sell_in=10, quality=2)
         gilded_rose = GildedRose([item])
         gilded_rose.update_quality()
         self.assertEquals(9, item.sell_in)
 
     def test_sulfuras_sell_in_and_quality(self):
-        item = Item(name="Sulfuras, Hand of Ragnaros", sell_in=10, quality=2)
+        item = FactoryItem.create_new_item(name="Sulfuras, Hand of Ragnaros", sell_in=10, quality=2)
         gilded_rose = GildedRose([item])
         gilded_rose.update_quality()
 
@@ -51,7 +52,7 @@ class GildedRoseTest(unittest.TestCase):
         self.assertEquals(2, item.quality)
 
     def test_backstage_quality_for_less_than_ten_days(self):
-        item = Item(name="Backstage passes to a TAFKAL80ETC concert", sell_in=9, quality=2)
+        item = FactoryItem.create_new_item(name="Backstage passes to a TAFKAL80ETC concert", sell_in=9, quality=2)
         gilded_rose = GildedRose([item])
         gilded_rose.update_quality()
         self.assertEquals(8, item.sell_in)
@@ -60,7 +61,7 @@ class GildedRoseTest(unittest.TestCase):
         self.assertEquals(4, item.quality)
 
     def test_backstage_quality_for_less_than_five_days(self):
-        item = Item(name="Backstage passes to a TAFKAL80ETC concert", sell_in=5, quality=2)
+        item = FactoryItem.create_new_item(name="Backstage passes to a TAFKAL80ETC concert", sell_in=5, quality=2)
         gilded_rose = GildedRose([item])
         gilded_rose.update_quality()
         self.assertEquals(4, item.sell_in)
@@ -69,7 +70,7 @@ class GildedRoseTest(unittest.TestCase):
         self.assertEquals(5, item.quality)
 
     def test_backstage_quality_when_concert_is_over(self):
-        item = Item(name="Backstage passes to a TAFKAL80ETC concert", sell_in=0, quality=2)
+        item = FactoryItem.create_new_item(name="Backstage passes to a TAFKAL80ETC concert", sell_in=0, quality=2)
         gilded_rose = GildedRose([item])
         gilded_rose.update_quality()
         self.assertEquals(-1, item.sell_in)
@@ -77,6 +78,15 @@ class GildedRoseTest(unittest.TestCase):
         # For backstage, quality gets to 0 when concert is over that is sell_in <= 0
         self.assertEquals(0, item.quality)
 
+    def test_conjured_quality(self):
+        item = FactoryItem.create_new_item(name="Conjured", sell_in=10, quality=2)
+        gilded_rose = GildedRose([item])
+        gilded_rose.update_quality()
+        self.assertEquals(9, item.sell_in)
+
+        # For conjured, quality is reduced by 2
+        self.assertEquals(0, item.quality)
+
         
 if __name__ == '__main__':
     unittest.main()