GildedRose Refactoring changes

Java/src/main/java/com/gildedrose/GildedRose.java

@@ -1,5 +1,8 @@
 package com.gildedrose;
 
+import com.gildedrose.updaters.ItemUpdater;
+import com.gildedrose.updaters.ItemUpdaterFactory;
+
 class GildedRose {
     Item[] items;
 
@@ -8,55 +11,9 @@ class GildedRose {
     }
 
     public void updateQuality() {
-        for (int i = 0; i < items.length; i++) {
+        for (Item item : items) {
-            if (!items[i].name.equals("Aged Brie")
+            ItemUpdater updater = ItemUpdaterFactory.getUpdater(item);
-                    && !items[i].name.equals("Backstage passes to a TAFKAL80ETC concert")) {
+            updater.update();
-                if (items[i].quality > 0) {
-                    if (!items[i].name.equals("Sulfuras, Hand of Ragnaros")) {
-                        items[i].quality = items[i].quality - 1;
-                    }
-                }
-            } else {
-                if (items[i].quality < 50) {
-                    items[i].quality = items[i].quality + 1;
-
-                    if (items[i].name.equals("Backstage passes to a TAFKAL80ETC concert")) {
-                        if (items[i].sellIn < 11) {
-                            if (items[i].quality < 50) {
-                                items[i].quality = items[i].quality + 1;
-                            }
-                        }
-
-                        if (items[i].sellIn < 6) {
-                            if (items[i].quality < 50) {
-                                items[i].quality = items[i].quality + 1;
-                            }
-                        }
-                    }
-                }
-            }
-
-            if (!items[i].name.equals("Sulfuras, Hand of Ragnaros")) {
-                items[i].sellIn = items[i].sellIn - 1;
-            }
-
-            if (items[i].sellIn < 0) {
-                if (!items[i].name.equals("Aged Brie")) {
-                    if (!items[i].name.equals("Backstage passes to a TAFKAL80ETC concert")) {
-                        if (items[i].quality > 0) {
-                            if (!items[i].name.equals("Sulfuras, Hand of Ragnaros")) {
-                                items[i].quality = items[i].quality - 1;
-                            }
-                        }
-                    } else {
-                        items[i].quality = items[i].quality - items[i].quality;
-                    }
-                } else {
-                    if (items[i].quality < 50) {
-                        items[i].quality = items[i].quality + 1;
-                    }
-                }
-            }
         }
     }
 }

Java/src/main/java/com/gildedrose/GildedRoseConstants.java

@@ -0,0 +1,8 @@
+package com.gildedrose;
+
+public class GildedRoseConstants {
+    public static final String AGED_BRIE = "Aged Brie";
+    public static final String SULFURAS = "Sulfuras, Hand of Ragnaros";
+    public static final String BACKSTAGE_PASS = "Backstage passes to a TAFKAL80ETC concert";
+    public static final String CONJURED = "conjured";
+}

Java/src/main/java/com/gildedrose/updaters/AgedBrieUpdater.java

@@ -0,0 +1,18 @@
+package com.gildedrose.updaters;
+
+import com.gildedrose.Item;
+
+public class AgedBrieUpdater extends ItemUpdater {
+    public AgedBrieUpdater(Item item) {
+        super(item);
+    }
+
+    @Override
+    public void update() {
+        increaseQuality(1);
+        decreaseSellIn();
+        if (item.sellIn < 0) {
+            increaseQuality(1);
+        }
+    }
+}

Java/src/main/java/com/gildedrose/updaters/BackstagePassUpdater.java

@@ -0,0 +1,23 @@
+package com.gildedrose.updaters;
+
+import com.gildedrose.Item;
+
+public class BackstagePassUpdater extends ItemUpdater {
+    public BackstagePassUpdater(Item item) {
+        super(item);
+    }
+
+    @Override
+    public void update() {
+        if (item.sellIn <= 0) {
+            item.quality = 0;
+        } else if (item.sellIn <= 5) {
+            increaseQuality(3);
+        } else if (item.sellIn <= 10) {
+            increaseQuality(2);
+        } else {
+            increaseQuality(1);
+        }
+        decreaseSellIn();
+    }
+}

Java/src/main/java/com/gildedrose/updaters/ConjuredItemUpdater.java

@@ -0,0 +1,18 @@
+package com.gildedrose.updaters;
+
+import com.gildedrose.Item;
+
+public class ConjuredItemUpdater extends ItemUpdater {
+    public ConjuredItemUpdater(Item item) {
+        super(item);
+    }
+
+    @Override
+    public void update() {
+        decreaseQuality(2);
+        decreaseSellIn();
+        if (item.sellIn < 0) {
+            decreaseQuality(2);
+        }
+    }
+}

Java/src/main/java/com/gildedrose/updaters/ItemUpdater.java

@@ -0,0 +1,25 @@
+package com.gildedrose.updaters;
+
+import com.gildedrose.Item;
+
+public abstract class ItemUpdater {
+    protected final Item item;
+
+    public ItemUpdater(Item item) {
+        this.item = item;
+    }
+
+    public abstract void update();
+
+    protected void increaseQuality(int amount) {
+        item.quality = Math.min(50, item.quality + amount);
+    }
+
+    protected void decreaseQuality(int amount) {
+        item.quality = Math.max(0, item.quality - amount);
+    }
+
+    protected void decreaseSellIn() {
+        item.sellIn--;
+    }
+}

Java/src/main/java/com/gildedrose/updaters/ItemUpdaterFactory.java

@@ -0,0 +1,23 @@
+package com.gildedrose.updaters;
+
+import com.gildedrose.Item;
+
+import static com.gildedrose.GildedRoseConstants.*;
+
+public class ItemUpdaterFactory {
+    public static ItemUpdater getUpdater(Item item) {
+        String name = item.name;
+
+        if (name.equals(AGED_BRIE)) {
+            return new AgedBrieUpdater(item);
+        } else if (name.equals(SULFURAS)) {
+            return new SulfurasUpdater(item);
+        } else if (name.equals(BACKSTAGE_PASS)) {
+            return new BackstagePassUpdater(item);
+        } else if (name.toLowerCase().contains(CONJURED)) {
+            return new ConjuredItemUpdater(item);
+        } else {
+            return new NormalItemUpdater(item);
+        }
+    }
+}

Java/src/main/java/com/gildedrose/updaters/NormalItemUpdater.java

@@ -0,0 +1,18 @@
+package com.gildedrose.updaters;
+
+import com.gildedrose.Item;
+
+public class NormalItemUpdater extends ItemUpdater {
+    public NormalItemUpdater(Item item) {
+        super(item);
+    }
+
+    @Override
+    public void update() {
+        decreaseQuality(1);
+        decreaseSellIn();
+        if (item.sellIn < 0) {
+            decreaseQuality(1);
+        }
+    }
+}

Java/src/main/java/com/gildedrose/updaters/SulfurasUpdater.java

@@ -0,0 +1,14 @@
+package com.gildedrose.updaters;
+
+import com.gildedrose.Item;
+
+public class SulfurasUpdater extends ItemUpdater {
+    public SulfurasUpdater(Item item) {
+        super(item);
+    }
+
+    @Override
+    public void update() {
+        // Legendary item, do nothing
+    }
+}

Java/src/test/java/com/gildedrose/GildedRoseTest.java

@@ -2,16 +2,34 @@ package com.gildedrose;
 
 import org.junit.jupiter.api.Test;
 
+import static com.gildedrose.GildedRoseConstants.*;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
-class GildedRoseTest {
+public class GildedRoseTest {
-
     @Test
-    void foo() {
+    void agedBrieIncreasesInQuality() {
-        Item[] items = new Item[] { new Item("foo", 0, 0) };
+        Item[] items = new Item[] { new Item(AGED_BRIE, 2, 0) };
         GildedRose app = new GildedRose(items);
         app.updateQuality();
-        assertEquals("fixme", app.items[0].name);
+        assertEquals(1, items[0].quality);
+        assertEquals(1, items[0].sellIn);
     }
 
+    @Test
+    void sulfurasDoesNotChange() {
+        Item[] items = new Item[] { new Item(SULFURAS, 0, 80) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        assertEquals(80, items[0].quality);
+        assertEquals(0, items[0].sellIn);
+    }
+
+    @Test
+    void backstagePassIncreasesCorrectly() {
+        Item[] items = new Item[] { new Item(BACKSTAGE_PASS, 5, 10) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        assertEquals(13, items[0].quality);
+        assertEquals(4, items[0].sellIn);
+    }
 }