Fixed update function in gilded rose and added unit tests

.gitignore

@@ -1,7 +1,2 @@
-*.pyc
-.cache
-.coverage
-.idea/
-*.iml
-.pytest_cache
-.approval_tests_temp
+# Created by venv; see https://docs.python.org/3/library/venv.html
+venv/

gilded_rose.py

@@ -4,37 +4,67 @@ class GildedRose(object):
 
     def __init__(self, items):
         self.items = items
+        for it in self.items:
+            self.clip(it)
 
-    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
+    def clip(self, it):
+        if it.name == "Sulfuras, Hand of Ragnaros":
+            return
+
+        if it.quality < 0:
+            it.quality = 0
+        elif it.quality > 50:
+            it.quality = 50
+
+    def handle_special_item(self, item) -> bool:
+        item.sell_in -= 1
+
+        # handle aged brie
+        if item.name == "Aged Brie":
+            item.quality += 1
+            return True
+        # handle passes
+        elif "Backstage passes" in item.name:
+            # apply rules for backstage passes quality
+            if item.sell_in <= 0:
+                item.quality = 0
+            elif item.sell_in <= 5:
+                item.quality += 3
+            elif item.sell_in <= 10:
+                item.quality += 2
+            else:
+                item.quality += 1
+
+            return True
+        # handle sulfuras
+        elif item.name == "Sulfuras, Hand of Ragnaros":
+            item.sell_in += 1
+            return True
+        else:
+            return False
+
+    def handle_regular_item(self, item) -> None:
+        item.sell_in -= 1
+        expired_multiplier = 1
+
+        if item.sell_in  < 0:
+            expired_multiplier = 2
+
+        if "Conjured" in item.name:
+            item.quality -= 2 * expired_multiplier
+        else:
+            item.quality -= 1 * expired_multiplier
+
+    def update_quality(self) -> None:
+        for it in self.items:
+            is_special = self.handle_special_item(it)
+
+            if is_special:
+                pass
             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.handle_regular_item(it)
 
+            self.clip(it)
 
 class Item:
     def __init__(self, name, sell_in, quality):

tests/test_gilded_rose.py

@@ -5,12 +5,78 @@
 
 
 class GildedRoseTest(unittest.TestCase):
+    def setUp(self):
+        self.regular_items = [
+            Item("CPU Components", 3, 12),
+            Item("Mega Trash", -2, -10),
+            Item("Trash", 1, -10),
+            Item("\"As I\'ve Written\"", 30, 100),
+            Item("Cheese of Truth", 10, 20),
+            Item("Rotten Apples", -10, -50)
+        ]
+        self.conjured_items = [ 
+            Item("Conjured Burger", 13, 13),
+            Item("Conjured +3 Fire DMG Ring", 40, 60),
+            Item("Conjured Cursed Tome", 100, 30)
+        ]
+        self.backstage_pass_items = [
+            Item("Backstage passes to Gandalf concert", 9, 30),
+            Item("Backstage passes to Haggard concert", 15, 10),
+            Item("Backstage passes to Conjured Guitarists concert", 5, 0),
+            Item("Backstage passes to HelloWorld concert", 0, 33)
+        ]
+        self.aged_brie_items = [
+            Item("Aged Brie", 5, 12),
+            Item("Aged Brie", -10, -100)
+        ]
+
+        self.sulfuras_items = [
+            Item("Sulfuras, Hand of Ragnaros", 100, 60),
+            Item("Sulfuras, Hand of Ragnaros", 999, 60)
+        ]
+
+
     def test_foo(self):
         items = [Item("foo", 0, 0)]
         gilded_rose = GildedRose(items)
         gilded_rose.update_quality()
-        self.assertEqual("fixme", items[0].name)
+        self.assertEqual("foo", items[0].name)
+
+    # this checks if all items degrade according to the list [11, 0, 0, 49, 19, 0]
+    def test_regular_items(self):
+        gilded_rose = GildedRose(self.regular_items)
+        values_list = [11, 0, 0, 49, 19, 0]
+
+        gilded_rose.update_quality()
+        self.assertListEqual(values_list, [ it.quality for it in self.regular_items ])
+
+    def test_brie(self):
+        gilded_rose = GildedRose(self.aged_brie_items)
+        values_list = [13, 1]
+
+        gilded_rose.update_quality()
+        self.assertListEqual(values_list, [ it.quality for it in self.aged_brie_items ])
 
+    def test_conjured_items(self):
+        gilded_rose = GildedRose(self.conjured_items)
+        values_list = [11, 48, 28]
+
+        gilded_rose.update_quality()
+        self.assertListEqual(values_list, [ it.quality for it in self.conjured_items ])
+
+    def test_backstage_passes(self):
+        gilded_rose = GildedRose(self.backstage_pass_items)
+        values_list = [32, 11, 3, 0]
+
+        gilded_rose.update_quality()
+        self.assertListEqual(values_list, [ it.quality for it in self.backstage_pass_items ])
+
+    def test_sulfuras(self):
+        gilded_rose = GildedRose(self.sulfuras_items)
+        values_list = [60, 60]
+
+        gilded_rose.update_quality()
+        self.assertListEqual(values_list, [ it.quality for it in self.sulfuras_items ])
 
 if __name__ == '__main__':
     unittest.main()