ktlo-0001 - Refactor update quality method and increase use case and edge case test coverage

python/gilded_rose.py

@@ -1,39 +1,96 @@
 # -*- coding: utf-8 -*-
 
 class GildedRose(object):
+    MAX_NON_LEGENDARY_QUALITY = 50
+    STATIC_LEGENDARY_QUALITY = 80
+    STANDARD_INCREMENT = 1
 
     def __init__(self, items):
         self.items = items
 
+    @staticmethod
+    def _is_static_item(name: str) -> bool:
+        static_items = [
+            'Sulfuras, Hand of Ragnaros',
+        ]
+        return name in static_items
+
+    @staticmethod
+    def _is_inverse_quality_item(name: str) -> bool:
+        inverse_quality_items = [
+            'Aged Brie',
+        ]
+        return name in inverse_quality_items
+
+    @staticmethod
+    def _is_ranged_rule_based_item(name: str) -> bool:
+        inverse_quality_items = [
+            'Backstage passes to a TAFKAL80ETC concert',
+        ]
+        return name in inverse_quality_items
+
+    @staticmethod
+    def _is_double_increment_keyword_item(name: str) -> bool:
+        ranged_rule_based_items = [
+            'Conjured',
+        ]
+        for keyword in ranged_rule_based_items:
+            if keyword in name:
+                return True
+            else:
+                return False
+
+    def _increase_quality(self, item):
+        if item.quality < self.MAX_NON_LEGENDARY_QUALITY:
+            item.quality += self.STANDARD_INCREMENT
+
+    def _update_inverse_quality_item(self, item):
+        self._increase_quality(item)
+        item.sell_in -= self.STANDARD_INCREMENT
+        if item.sell_in < 0:
+            self._increase_quality(item)
+
+    def _update_ranged_rule_based_item(self, item):
+        if item.sell_in < 6:
+            item.quality += self.STANDARD_INCREMENT * 3
+        elif item.sell_in < 11:
+            item.quality += self.STANDARD_INCREMENT * 2
+        else:
+            item.quality += self.STANDARD_INCREMENT
+        item.sell_in -= self.STANDARD_INCREMENT
+        if item.quality > self.MAX_NON_LEGENDARY_QUALITY:
+            item.quality = self.MAX_NON_LEGENDARY_QUALITY
+        if item.sell_in < 0:
+            item.quality = 0
+
+    def _update_item(self, item, increment):
+        if item.quality > 0:
+            item.quality -= increment
+        item.sell_in -= self.STANDARD_INCREMENT
+        if item.sell_in < 0 < item.quality:
+            item.quality -= increment
+
     def update_quality(self):
         for item in self.items:
-            if item.name != "Aged Brie" and item.name != "Backstage passes to a TAFKAL80ETC concert":
-                if item.quality > 0:
-                    if item.name != "Sulfuras, Hand of Ragnaros":
-                        item.quality = item.quality - 1
+            # Catch static items
+            if self._is_static_item(item.name):
+                item.quality = self.STATIC_LEGENDARY_QUALITY
+                continue
+            # Catch items with inverse quality update
+            elif self._is_inverse_quality_item(item.name):
+                self._update_inverse_quality_item(item)
+                continue
+            # Catch items with range based rule
+            elif self._is_ranged_rule_based_item(item.name):
+                self._update_ranged_rule_based_item(item)
+                continue
+            # Catch conjured items
+            elif self._is_double_increment_keyword_item(item.name):
+                self._update_item(item, self.STANDARD_INCREMENT * 2)
+                continue
+            # Catch all other 'normal' items
             else:
-                if item.quality < 50:
-                    item.quality = item.quality + 1
-                    if item.name == "Backstage passes to a TAFKAL80ETC concert":
-                        if item.sell_in < 11:
-                            if item.quality < 50:
-                                item.quality = item.quality + 1
-                        if item.sell_in < 6:
-                            if item.quality < 50:
-                                item.quality = item.quality + 1
-            if item.name != "Sulfuras, Hand of Ragnaros":
-                item.sell_in = item.sell_in - 1
-            if item.sell_in < 0:
-                if item.name != "Aged Brie":
-                    if item.name != "Backstage passes to a TAFKAL80ETC concert":
-                        if item.quality > 0:
-                            if item.name != "Sulfuras, Hand of Ragnaros":
-                                item.quality = item.quality - 1
-                    else:
-                        item.quality = item.quality - item.quality
-                else:
-                    if item.quality < 50:
-                        item.quality = item.quality + 1
+                self._update_item(item, self.STANDARD_INCREMENT)
 
 
 class Item:

python/test_gilded_rose.py

@@ -9,8 +9,92 @@ class GildedRoseTest(unittest.TestCase):
         items = [Item("foo", 0, 0)]
         gilded_rose = GildedRose(items)
         gilded_rose.update_quality()
-        self.assertEquals("fixme", items[0].name)
+        self.assertEquals("foo", items[0].name)
+
+    def test_item_quality_degrades_double_when_sell_in_negative(self):
+        items = [Item("foo", -1, 15)]
+        gilded_rose = GildedRose(items)
+        gilded_rose.update_quality()
+        self.assertEquals(13, items[0].quality)
+
+    def test_item_quality_wont_go_negative(self):
+        items = [Item("foo", 5, 0)]
+        gilded_rose = GildedRose(items)
+        gilded_rose.update_quality()
+        self.assertEquals(0, items[0].quality)
+
+    def test_aged_brie_quality_cap(self):
+        items = [Item("Aged Brie", 10, 50)]
+        gilded_rose = GildedRose(items)
+        gilded_rose.update_quality()
+        self.assertEquals(50, items[0].quality)
+
+    def test_aged_brie_sell_in_decrease(self):
+        items = [Item("Aged Brie", 30, 30)]
+        gilded_rose = GildedRose(items)
+        gilded_rose.update_quality()
+        self.assertEquals(29, items[0].sell_in)
+
+    def test_aged_brie_quality_increase(self):
+        items = [Item("Aged Brie", 30, 30)]
+        gilded_rose = GildedRose(items)
+        gilded_rose.update_quality()
+        self.assertEquals(31, items[0].quality)
+
+    def test_aged_brie_quality_increase_double_when_sell_in_negative(self):
+        items = [Item("Aged Brie", -10, 20)]
+        gilded_rose = GildedRose(items)
+        gilded_rose.update_quality()
+        self.assertEquals(22, items[0].quality)
+
+    def test_sulfuras_quality_doesnt_change(self):
+        items = [Item("Sulfuras, Hand of Ragnaros", 10, 80)]
+        gilded_rose = GildedRose(items)
+        gilded_rose.update_quality()
+        self.assertEquals(80, items[0].quality)
+
+    def test_sulfuras_when_passed_sell_in(self):
+        items = [Item("Sulfuras, Hand of Ragnaros", -10, 80)]
+        gilded_rose = GildedRose(items)
+        gilded_rose.update_quality()
+        self.assertEquals(80, items[0].quality)
+
+    def test_backstage_pass_increases_quality(self):
+        items = [Item("Backstage passes to a TAFKAL80ETC concert", 20, 20)]
+        gilded_rose = GildedRose(items)
+        gilded_rose.update_quality()
+        self.assertEquals(21, items[0].quality)
+
+    def test_backstage_pass_10_days_to_go(self):
+        items = [Item("Backstage passes to a TAFKAL80ETC concert", 10, 20)]
+        gilded_rose = GildedRose(items)
+        gilded_rose.update_quality()
+        self.assertEquals(22, items[0].quality)
+
+    def test_backstage_pass_5_days_to_go(self):
+        items = [Item("Backstage passes to a TAFKAL80ETC concert", 5, 20)]
+        gilded_rose = GildedRose(items)
+        gilded_rose.update_quality()
+        self.assertEquals(23, items[0].quality)
+
+    def test_backstage_pass_quality_after_concert(self):
+        items = [Item("Backstage passes to a TAFKAL80ETC concert", 0, 30)]
+        gilded_rose = GildedRose(items)
+        gilded_rose.update_quality()
+        self.assertEquals(0, items[0].quality)
+
+    def test_conjured_item_quality_decrease(self):
+        items = [Item("Conjured", 10, 30)]
+        gilded_rose = GildedRose(items)
+        gilded_rose.update_quality()
+        self.assertEquals(28, items[0].quality)
+
+    def test_conjured_item_quality_increase_double_when_sell_in_negative(self):
+        items = [Item("Conjured", 0, 30)]
+        gilded_rose = GildedRose(items)
+        gilded_rose.update_quality()
+        self.assertEquals(26, items[0].quality)
+
 
-        
 if __name__ == '__main__':
     unittest.main()

python/texttest_fixture.py

@@ -4,18 +4,18 @@ from __future__ import print_function
 from gilded_rose import *
 
 if __name__ == "__main__":
-    print ("OMGHAI!")
+    print("OMGHAI!")
     items = [
-             Item(name="+5 Dexterity Vest", sell_in=10, quality=20),
-             Item(name="Aged Brie", sell_in=2, quality=0),
-             Item(name="Elixir of the Mongoose", sell_in=5, quality=7),
-             Item(name="Sulfuras, Hand of Ragnaros", sell_in=0, quality=80),
-             Item(name="Sulfuras, Hand of Ragnaros", sell_in=-1, quality=80),
-             Item(name="Backstage passes to a TAFKAL80ETC concert", sell_in=15, quality=20),
-             Item(name="Backstage passes to a TAFKAL80ETC concert", sell_in=10, quality=49),
-             Item(name="Backstage passes to a TAFKAL80ETC concert", sell_in=5, quality=49),
-             Item(name="Conjured Mana Cake", sell_in=3, quality=6),  # <-- :O
-            ]
+        Item(name="+5 Dexterity Vest", sell_in=10, quality=20),
+        Item(name="Aged Brie", sell_in=2, quality=0),
+        Item(name="Elixir of the Mongoose", sell_in=5, quality=7),
+        Item(name="Sulfuras, Hand of Ragnaros", sell_in=0, quality=80),
+        Item(name="Sulfuras, Hand of Ragnaros", sell_in=-1, quality=80),
+        Item(name="Backstage passes to a TAFKAL80ETC concert", sell_in=15, quality=20),
+        Item(name="Backstage passes to a TAFKAL80ETC concert", sell_in=10, quality=49),
+        Item(name="Backstage passes to a TAFKAL80ETC concert", sell_in=5, quality=49),
+        Item(name="Conjured Mana Cake", sell_in=3, quality=6),  # <-- :O
+    ]
 
     days = 2
     import sys