Adding unit tests and refactoring - looks good ;-)

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

@@ -1,62 +1,89 @@
 package com.gildedrose;
 
 class GildedRose {
+
+    public static final String SULFURAS = "Sulfuras, Hand of Ragnaros";
+    public static final String CHEESE = "Aged Brie";
+    //TODO: brainstorm the naming a bit here.
+    public static final String BACKSTAGE_PASSES_TO_A_TAFKAL_80_ETC_CONCERT
+        = "Backstage passes to a TAFKAL80ETC concert";
+
     Item[] items;
 
     public GildedRose(Item[] items) {
         this.items = items;
     }
 
+    /**
+     * Update the staet of the items.
+     */
     public void updateQuality() {
-        for (int i = 0; i < items.length; i++) {
+        for (Item item : items) {
-            if (!items[i].name.equals("Aged Brie")
+            if (!item.name.equals(CHEESE)
-                    && !items[i].name.equals("Backstage passes to a TAFKAL80ETC concert")) {
+                && !item.name.equals(BACKSTAGE_PASSES_TO_A_TAFKAL_80_ETC_CONCERT)) {
-                if (items[i].quality > 0) {
+                if (item.quality > 0) {
-                    if (!items[i].name.equals("Sulfuras, Hand of Ragnaros")) {
+                    if (!item.name.equals(SULFURAS)) {
-                        items[i].quality = items[i].quality - 1;
+                        item.quality = item.quality - 1;
                     }
                 }
             } else {
-                if (items[i].quality < 50) {
+                dealWithPasses(item);
-                    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 (!item.name.equals("Sulfuras, Hand of Ragnaros")) {
-                            if (items[i].quality < 50) {
+                decrementSellIn(item);
-                                items[i].quality = items[i].quality + 1;
             }
+
+            if (item.sellIn < 0) {
+                if (!item.name.equals(CHEESE) &&
+                    !item.name.equals(BACKSTAGE_PASSES_TO_A_TAFKAL_80_ETC_CONCERT)) {
+                    dealWithExpiredItem(item);
+                } else {
+                    dealWithExpiredCheeseOrPasses(item);
                 }
             }
         }
     }
 
-            if (!items[i].name.equals("Sulfuras, Hand of Ragnaros")) {
+    private void decrementSellIn(Item item) {
-                items[i].sellIn = items[i].sellIn - 1;
+        item.sellIn = item.sellIn - 1;
     }
 
-            if (items[i].sellIn < 0) {
+    private void dealWithPasses(Item item) {
-                if (!items[i].name.equals("Aged Brie")) {
+        if (item.quality < 50) {
-                    if (!items[i].name.equals("Backstage passes to a TAFKAL80ETC concert")) {
+            item.quality = item.quality + 1;
-                        if (items[i].quality > 0) {
+
-                            if (!items[i].name.equals("Sulfuras, Hand of Ragnaros")) {
+            if (item.name.equals(BACKSTAGE_PASSES_TO_A_TAFKAL_80_ETC_CONCERT)) {
-                                items[i].quality = items[i].quality - 1;
+                if (item.sellIn < 11) {
+                    if (item.quality < 50) {
+                        item.quality = item.quality + 1;
                     }
                 }
+
+                // If the sellIn is 5 days or fewer add to the quality again
+                if (item.sellIn < 6) {
+                    item.quality = item.quality + 1;
+                }
+            }
+        }
+    }
+
+    private void dealWithExpiredItem(Item item) {
+        if (item.quality > 0) {
+            if (!item.name.equals(SULFURAS)) {
+                item.quality = item.quality - 1;
+            }
         } else {
-                        items[i].quality = items[i].quality - items[i].quality;
+            item.quality = 0;
         }
+    }
+
+    private void dealWithExpiredCheeseOrPasses(Item item) {
+        if (item.quality < 50 && !item.name.equals(BACKSTAGE_PASSES_TO_A_TAFKAL_80_ETC_CONCERT)) {
+            item.quality = item.quality + 1;
         } else {
-                    if (items[i].quality < 50) {
+            item.quality = 0;
-                        items[i].quality = items[i].quality + 1;
-                    }
-                }
-            }
         }
     }
+
 }

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

@@ -18,4 +18,32 @@ public class Item {
     public String toString() {
         return this.name + ", " + this.sellIn + ", " + this.quality;
     }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+
+        Item item = (Item) o;
+
+        if (sellIn != item.sellIn) {
+            return false;
+        }
+        if (quality != item.quality) {
+            return false;
+        }
+        return name != null ? name.equals(item.name) : item.name == null;
+    }
+
+    @Override
+    public int hashCode() {
+        int result = name != null ? name.hashCode() : 0;
+        result = 31 * result + sellIn;
+        result = 31 * result + quality;
+        return result;
+    }
 }

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

@@ -7,11 +7,82 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 class GildedRoseTest {
 
     @Test
-    void foo() {
+    void testNormalDegrade() {
-        Item[] items = new Item[] { new Item("foo", 0, 0) };
+        Item testItem = new Item("test_item", 3, 10);
+        Item[] items = new Item[] {testItem};
         GildedRose app = new GildedRose(items);
         app.updateQuality();
-        assertEquals("fixme", app.items[0].name);
+        Item updatedItem = app.items[0];
+        assertEquals(new Item("test_item", 2, 9), updatedItem);
     }
 
+    @Test
+    void testPastSellInDegrade() {
+        Item testItem = new Item("test_item", 0, 10);
+        Item[] items = new Item[] {testItem};
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        Item updatedItem = app.items[0];
+        assertEquals(new Item("test_item", -1, 8), updatedItem);
+    }
+
+    @Test
+    void testQualityMustNotEverGoUnderZero() {
+        Item testItem = new Item("test_item", 5, 0);
+        Item[] items = new Item[] {testItem};
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        Item updatedItem = app.items[0];
+        assertEquals(0, testItem.quality);
+    }
+
+    @Test
+    void testAgedBrieGetsBetterWithAge() {
+        Item testItem = new Item("Aged Brie", 5, 10);
+        Item[] items = new Item[] {testItem};
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        Item updatedItem = app.items[0];
+        assertEquals(new Item("Aged Brie", 4, 11), updatedItem);
+    }
+
+    @Test
+    void testQualityIsCappedAt50() {
+        Item testItem = new Item("Aged Brie", 5, 50);
+        Item[] items = new Item[] {testItem};
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        Item updatedItem = app.items[0];
+        assertEquals(50, updatedItem.quality);
+    }
+
+    @Test
+    void testBackstagePass() {
+        Item testItem = new Item("Backstage passes to a TAFKAL80ETC concert", 6, 10);
+        Item[] items = new Item[] {testItem};
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        Item updatedItem = app.items[0];
+        assertEquals(12, updatedItem.quality);
+    }
+
+    @Test
+    void testBackstagePassWhenLessThan3DaysRemaining() {
+        Item testItem = new Item("Backstage passes to a TAFKAL80ETC concert", 3, 10);
+        Item[] items = new Item[] {testItem};
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        Item updatedItem = app.items[0];
+        assertEquals(13, updatedItem.quality);
+    }
+
+    @Test
+    void testExpiredBackstagePass() {
+        Item testItem = new Item("Backstage passes to a TAFKAL80ETC concert", 0, 10);
+        Item[] items = new Item[] {testItem};
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        Item updatedItem = app.items[0];
+        assertEquals(0, updatedItem.quality);
+    }
 }