Added ItemUpdater Interface with Implementations for each item class. Added Tests. Updated GildedRose updateItems() method.

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

@@ -1,62 +1,95 @@
 package com.gildedrose;
+import com.gildedrose.ItemUpdater;
 
 class GildedRose {
-    Item[] items;
+    Item[] items; // Inventory*
 
     public GildedRose(Item[] items) {
         this.items = items;
     }
-
     public void updateQuality() {
-        for (int i = 0; i < items.length; i++) {
+        // Instantiate updaters for each item type. (Can I instantiate itemupdater only when i need it?)
-            if (!items[i].name.equals("Aged Brie")
+        ItemUpdater defaultUpdater = new DefaultItemUpdater();
-                    && !items[i].name.equals("Backstage passes to a TAFKAL80ETC concert")) {
+        ItemUpdater agedBrieUpdater = new AgedBrieUpdater();
-                if (items[i].quality > 0) {
+        ItemUpdater backstagePassUpdater = new BackStagePassUpdater();
-                    if (!items[i].name.equals("Sulfuras, Hand of Ragnaros")) {
+        ItemUpdater conjuredItemUpdater = new ConjuredItemUpdater();
-                        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")) {
+        // Iterate through items and call corresponding updater
-                        if (items[i].sellIn < 11) {
+        for (Item item : items) {
-                            if (items[i].quality < 50) {
+            String name = item.name;
-                                items[i].quality = items[i].quality + 1;
+            switch (name) {
-                            }
+                case "Aged Brie":
-                        }
+                    agedBrieUpdater.update(item);
-
+                    break;
-                        if (items[i].sellIn < 6) {
+                case "Backstage passes to a TAFKAL80ETC concert":
-                            if (items[i].quality < 50) {
+                    backstagePassUpdater.update(item);
-                                items[i].quality = items[i].quality + 1;
+                    break;
-                            }
+                case "Sulfuras, Hand of Ragnaros":
-                        }
+                    break;
-                    }
+                case "Conjured":
-                }
+                    conjuredItemUpdater.update(item);
-            }
+                    break;
-
+                default:
-            if (!items[i].name.equals("Sulfuras, Hand of Ragnaros")) {
+                    defaultUpdater.update(item);
-                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;
-                    }
-                }
             }
         }
     }
-}
+
+
+
+//    /*
+//        Aged Brie increases in quality the older it gets.
+//     */
+//    private void updateAgedBrie(Item item) {
+//        if (item.quality == 50)
+//            return;
+//        item.quality = item.quality + 1;
+//        // Do I have to decrease sellIn?
+//    }
+//
+//
+//    private void updateAnyItem(Item item) {
+//        if (item.quality <= 0 || item.sellIn <= 0)
+//            return;
+//        if (item.sellIn > 0)
+//            item.quality = item.quality - 1;
+//        else
+//            item.quality = item.quality - 2;
+//
+//        item.sellIn = item.sellIn - 1;
+//    }
+//
+//    /*
+//        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
+//     */
+//    private void updateBackStageTickets(Item item) {
+//        if (item.sellIn <= 0) {
+//            item.quality = 0;
+//        } else if (item.quality >= 50 && item.sellIn > 0) {
+//            item.sellIn--;
+//        } else if (item.sellIn < 10 && item.quality > 5) {
+//            item.quality = item.quality + 2;
+//            item.sellIn--;
+//        } else if (item.sellIn < 5) {
+//            item.quality = item.quality + 3;
+//            item.sellIn--;
+//        }
+//    }
+//
+//
+//    /*
+//        "Conjured" items degrade in Quality twice as fast as normal items
+//     */
+//        private void updateConjured (Item item){
+//            if (item.quality <= 0 || item.sellIn <= 0)
+//                return;
+//            if (item.sellIn > 0)
+//                item.quality = item.quality - 2;
+//            else
+//                item.quality = item.quality - 4;
+//            item.sellIn = item.sellIn - 1;
+//        }
+    }
+

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

@@ -0,0 +1,52 @@
+package com.gildedrose;
+
+public interface ItemUpdater {
+    void update(Item item);
+}
+
+class DefaultItemUpdater implements ItemUpdater {
+    @Override
+    public void update(Item item) {
+        decreaseQuality(item);
+        item.sellIn--;
+        if (item.sellIn < 0)
+            decreaseQuality(item);
+    }
+
+    protected void decreaseQuality(Item item) {
+        if (item.quality > 0)
+            item.quality--;
+    }
+}
+
+class AgedBrieUpdater implements ItemUpdater {
+    @Override
+    public void update(Item item) {
+        if (item.quality < 50)
+            item.quality++;
+        item.sellIn--;
+    }
+}
+
+class BackStagePassUpdater implements ItemUpdater {
+    @Override
+    public void update(Item item) {
+        if (item.quality < 50)
+            item.quality++;
+        if (item.sellIn <= 10 && item.quality < 50)
+            item.quality++;
+        if (item.sellIn <= 5 && item.quality < 50)
+            item.quality++;
+        item.sellIn--;
+        if (item.sellIn < 0)
+            item.quality = 0;
+    }
+}
+
+class ConjuredItemUpdater extends DefaultItemUpdater {
+    @Override
+    protected void decreaseQuality(Item item) {
+        if (item.quality > 0)
+            item.quality -= 2;
+    }
+}

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

@@ -3,15 +3,96 @@ package com.gildedrose;
 import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 class GildedRoseTest {
 
     @Test
-    void foo() {
+    void ElixirDepreciates() throws Exception{
-        Item[] items = new Item[] { new Item("foo", 0, 0) };
+        Item[] items = new Item[]{new Item("Elixir", 0, 40)};
         GildedRose app = new GildedRose(items);
         app.updateQuality();
-        assertEquals("fixme", app.items[0].name);
+        app.updateQuality();
+        assertEquals(-2, app.items[0].sellIn);
+        assertEquals(36, app.items[0].quality);
+    }
+
+    // TODO Write test cases for each item. Check Edge cases.
+
+    @Test
+    void backStage_Pass_Expires_After_Concert() throws Exception {
+        Item[] items = new Item[]{new Item("Backstage passes to a TAFKAL80ETC concert", 2, 15)};
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        app.updateQuality();
+        app.updateQuality();
+        assertEquals(-1, app.items[0].sellIn);
+        assertEquals(0, app.items[0].quality);
+    }
+
+    @Test
+    public void backStage_quality_increases_twiceAsFast_10daysOrLess_before_concert() throws Exception {
+        Item[] items = new Item[]{new Item("Backstage passes to a TAFKAL80ETC concert", 10, 20)};
+        GildedRose app = new GildedRose(items);
+
+        app.updateQuality();
+
+        assertEquals(9, app.items[0].sellIn);
+        assertEquals(22, app.items[0].quality);
+    }
+
+    @Test
+    public void quality_Never_Below_zero() throws Exception {
+        Item[] items = new Item[]{new Item("Bread", 10, 0)};
+        GildedRose app = new GildedRose(items);
+
+        app.updateQuality();
+
+        assertEquals(9, app.items[0].sellIn);
+        assertEquals(0, app.items[0].quality);
+    }
+
+    @Test
+    public void sulfuras_hasConstant_quality_and_sellIn() throws Exception {
+        Item[] items = new Item[]{new Item("Sulfuras, Hand of Ragnaros", 8, 30)};
+        GildedRose app = new GildedRose(items);
+
+        app.updateQuality();
+
+        assertEquals(8, app.items[0].sellIn);
+        assertEquals(30, app.items[0].quality);
+    }
+
+    @Test
+    public void aged_brie_quality_isMax50() throws Exception {
+        Item[] items = new Item[]{new Item("Aged Brie", 10, 50)};
+        GildedRose app = new GildedRose(items);
+
+        app.updateQuality();
+
+        assertEquals(9, app.items[0].sellIn);
+        assertEquals(50, app.items[0].quality);
+    }
+
+    @Test
+    public void backStage_quality_isMax50() throws Exception {
+        Item[] items = new Item[]{new Item("Backstage passes to a TAFKAL80ETC concert", 10, 50)};
+        GildedRose app = new GildedRose(items);
+
+        app.updateQuality();
+
+        assertEquals(9, app.items[0].sellIn);
+        assertEquals(50, app.items[0].quality);
+    }
+    @Test
+    public void anyItem_quality_isMax50() throws Exception {
+        Item[] items = new Item[]{new Item("Bread", 10, 50)};
+        GildedRose app = new GildedRose(items);
+
+        app.updateQuality();
+
+        assertEquals(9, app.items[0].sellIn);
+        assertEquals(49, app.items[0].quality);
     }
 
 }

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

@@ -18,7 +18,7 @@ public class TexttestFixture {
 
         GildedRose app = new GildedRose(items);
 
-        int days = 2;
+        int days = 20;
         if (args.length > 0) {
             days = Integer.parseInt(args[0]) + 1;
         }