Java refactor

Java/chris-readme.txt

@@ -0,0 +1,7 @@
+ItemHolder is an abstract class that implements the update template (first update quality then sellIn).
+Concrete classes implement algorithm for each item type.
+ItemHolder object creation is put into its own factory class as it will change with new item types.
+
+Improvements:
+Test code is highly duplicated. I assume Junit has paramaterized tests, just didn't bother looking it up.
+ItemHolders do checks for max and min values. Maybe those belong in setSellIn/setQuality methods?

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

@@ -0,0 +1,24 @@
+package com.gildedrose;
+
+public class BackstagePassesHolder extends ItemHolder {
+
+    public BackstagePassesHolder(Item item) {
+        super(item);
+    }
+    public void updateQuality() {
+        if (this.item.sellIn > 10) {
+            this.item.quality += 1;
+        } else if (this.item.sellIn > 5) {
+            this.item.quality += 2;
+        } else if (this.item.sellIn > 0) {
+            this.item.quality += 3;
+        } else if (this.item.sellIn <= 0) {
+            this.item.quality = 0;
+        }
+        this.item.quality = Math.min(this.item.quality, 50);
+    }
+
+    public void updateSellIn() {
+      this.item.sellIn -= 1;
+    }
+}

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

@@ -0,0 +1,17 @@
+package com.gildedrose;
+
+public class BrieHolder extends ItemHolder {
+
+    public BrieHolder(Item item) {
+        super(item);
+    }
+    public void updateQuality() {
+        if (this.item.quality < 50) {
+            this.item.quality += 1;
+        }
+    }
+
+    public void updateSellIn() {
+      this.item.sellIn -= 1;
+    }
+}

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

@@ -0,0 +1,20 @@
+package com.gildedrose;
+
+public class GenericItemHolder extends ItemHolder {
+
+    public GenericItemHolder(Item item) {
+        super(item);
+    }
+    public void updateQuality() {
+        if (this.item.sellIn > 0) {
+            this.item.quality -= 1;
+        } else {
+            this.item.quality -= 2;
+        }
+        this.item.quality = Math.max(this.item.quality, 0);
+    }
+
+    public void updateSellIn() {
+      this.item.sellIn -= 1;
+    }
+}

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

@@ -2,61 +2,19 @@ package com.gildedrose;
 
 class GildedRose {
     Item[] items;
+    ItemHolder[] itemHolders;
 
     public GildedRose(Item[] items) {
         this.items = items;
+        this.itemHolders = new ItemHolder[items.length];
+        for (int i=0; i<items.length; i++) {
+            itemHolders[i] = ItemHolderFactory.createItemHolder(this.items[i]);
+        }
     }
 
     public void updateQuality() {
         for (int i = 0; i < items.length; i++) {
-            if (!items[i].name.equals("Aged Brie")
+            itemHolders[i].update();
-                    && !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 {
-                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/ItemHolder.java

@@ -0,0 +1,17 @@
+package com.gildedrose;
+
+public abstract class ItemHolder {
+    Item item;
+
+    public ItemHolder(Item item){
+        this.item = item;
+    }
+
+    public void update() {
+        this.updateQuality();
+        this.updateSellIn();
+    }
+    abstract void updateQuality();
+
+    abstract void updateSellIn();
+}

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

@@ -0,0 +1,15 @@
+package com.gildedrose;
+
+public class ItemHolderFactory {
+    public static ItemHolder createItemHolder(Item item){
+        if (item.name == "Aged Brie") {
+            return new BrieHolder(item);
+        } else if (item.name == "Sulfuras, Hand of Ragnaros") {
+            return new SulfurasHolder(item);
+        } else if (item.name == "Backstage passes to a TAFKAL80ETC concert") {
+            return new BackstagePassesHolder(item);
+        } else {
+            return new GenericItemHolder(item);
+        }
+    }
+}

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

@@ -0,0 +1,11 @@
+package com.gildedrose;
+
+public class SulfurasHolder extends ItemHolder {
+
+    public SulfurasHolder(Item item) {
+        super(item);
+    }
+    public void updateQuality() {}
+
+    public void updateSellIn() {}
+}

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

@@ -7,11 +7,129 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 class GildedRoseTest {
 
     @Test
-    void foo() {
+    void add_item() {
         Item[] items = new Item[] { new Item("foo", 0, 0) };
         GildedRose app = new GildedRose(items);
+        assertEquals("foo", app.items[0].name);
+        assertEquals(0, app.items[0].sellIn);
+        assertEquals(0, app.items[0].quality);
+    }
+
+    @Test
+    void quality_decrease() {
+        Item[] items = new Item[] { new Item("foo", 1, 40) };
+        GildedRose app = new GildedRose(items);
         app.updateQuality();
-        assertEquals("fixme", app.items[0].name);
+        assertEquals(0, app.items[0].sellIn);
+        assertEquals(39, app.items[0].quality);
+    }
+
+    @Test
+    void fast_quality_decrease() {
+        Item[] items = new Item[] { new Item("foo", 0, 40) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        assertEquals(-1, app.items[0].sellIn);
+        assertEquals(38, app.items[0].quality);
+    }
+
+    @Test
+    void never_negative_quality() {
+        Item[] items = new Item[] { new Item("foo", -1, 1) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        assertEquals(-2, app.items[0].sellIn);
+        assertEquals(0, app.items[0].quality);
+    }
+
+    @Test
+    void aged_brie_quality_increase() {
+        Item[] items = new Item[] { new Item("Aged Brie", 5, 20) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        assertEquals(4, app.items[0].sellIn);
+        assertEquals(21, app.items[0].quality);
+    }
+
+    @Test
+    void aged_brie_max_quality_increase() {
+        Item[] items = new Item[] { new Item("Aged Brie", 5, 50) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        assertEquals(4, app.items[0].sellIn);
+        assertEquals(50, app.items[0].quality);
+    }
+
+    @Test
+    void sulfuras() {
+        Item[] items = new Item[] { new Item("Sulfuras, Hand of Ragnaros", 5, 80) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        assertEquals(5, app.items[0].sellIn);
+        assertEquals(80, app.items[0].quality);
+    }
+
+    @Test
+    void sulfuras_expired() {
+        Item[] items = new Item[] { new Item("Sulfuras, Hand of Ragnaros", -2, 80) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        assertEquals(-2, app.items[0].sellIn);
+        assertEquals(80, app.items[0].quality);
+    }
+
+    @Test
+    void backstage_passes_quality_increase() {
+        Item[] items = new Item[] { new Item("Backstage passes to a TAFKAL80ETC concert", 15, 20) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        assertEquals(14, app.items[0].sellIn);
+        assertEquals(21, app.items[0].quality);
+    }
+
+    @Test
+    void backstage_passes_max_quality() {
+        Item[] items = new Item[] { new Item("Backstage passes to a TAFKAL80ETC concert", 2, 50) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        assertEquals(1, app.items[0].sellIn);
+        assertEquals(50, app.items[0].quality);
+    }
+
+    @Test
+    void backstage_passes_day_ten() {
+        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
+    void backstage_passes_day_five() {
+        Item[] items = new Item[] { new Item("Backstage passes to a TAFKAL80ETC concert", 5, 20) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        assertEquals(4, app.items[0].sellIn);
+        assertEquals(23, app.items[0].quality);
+    }
+
+    @Test
+    void backstage_passes_day_zero() {
+        Item[] items = new Item[] { new Item("Backstage passes to a TAFKAL80ETC concert", 1, 20) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        assertEquals(0, app.items[0].sellIn);
+        assertEquals(23, app.items[0].quality);
+    }
+
+    @Test
+    void backstage_passes_expired() {
+        Item[] items = new Item[] { new Item("Backstage passes to a TAFKAL80ETC concert", 0, 20) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        assertEquals(-1, app.items[0].sellIn);
+        assertEquals(0, app.items[0].quality);
     }
 
 }

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

@@ -0,0 +1,120 @@
+package com.gildedrose;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ItemHolderFactoryTest {
+
+    @Test
+    void create_generic_item() {
+        ItemHolder itemHolder = ItemHolderFactory.createItemHolder(new Item("foo", 0, 0));
+        assertEquals("foo", itemHolder.item.name);
+        assertEquals(0, itemHolder.item.sellIn);
+        assertEquals(0, itemHolder.item.quality);
+    }
+
+    @Test
+    void quality_decrease() {
+        ItemHolder itemHolder = ItemHolderFactory.createItemHolder(new Item("foo", 1, 40));
+        itemHolder.update();
+        assertEquals(0, itemHolder.item.sellIn);
+        assertEquals(39, itemHolder.item.quality);
+    }
+
+    @Test
+    void fast_quality_decrease() {
+        ItemHolder itemHolder = ItemHolderFactory.createItemHolder(new Item("foo", 0, 40));
+        itemHolder.update();
+        assertEquals(-1, itemHolder.item.sellIn);
+        assertEquals(38, itemHolder.item.quality);
+    }
+
+    @Test
+    void never_negative_quality() {
+        ItemHolder itemHolder = ItemHolderFactory.createItemHolder(new Item("foo", -1, 1));
+        itemHolder.update();
+        assertEquals(-2, itemHolder.item.sellIn);
+        assertEquals(0, itemHolder.item.quality);
+    }
+
+    @Test
+    void aged_brie_quality_increase() {
+        ItemHolder itemHolder = ItemHolderFactory.createItemHolder(new Item("Aged Brie", 5, 20));
+        itemHolder.update();
+        assertEquals(4, itemHolder.item.sellIn);
+        assertEquals(21, itemHolder.item.quality);
+    }
+
+    @Test
+    void aged_brie_max_quality_increase() {
+        ItemHolder itemHolder = ItemHolderFactory.createItemHolder(new Item("Aged Brie", 5, 50));
+        itemHolder.update();
+        assertEquals(4, itemHolder.item.sellIn);
+        assertEquals(50, itemHolder.item.quality);
+    }
+
+    @Test
+    void sulfuras() {
+        ItemHolder itemHolder = ItemHolderFactory.createItemHolder(new Item("Sulfuras, Hand of Ragnaros", 5, 80));
+        itemHolder.update();
+        assertEquals(5, itemHolder.item.sellIn);
+        assertEquals(80, itemHolder.item.quality);
+    }
+
+    @Test
+    void sulfuras_expired() {
+        ItemHolder itemHolder = ItemHolderFactory.createItemHolder(new Item("Sulfuras, Hand of Ragnaros", -2, 80));
+        itemHolder.update();
+        assertEquals(-2, itemHolder.item.sellIn);
+        assertEquals(80, itemHolder.item.quality);
+    }
+
+    @Test
+    void backstage_passes_quality_increase() {
+        ItemHolder itemHolder = ItemHolderFactory.createItemHolder(new Item("Backstage passes to a TAFKAL80ETC concert", 15, 20));
+        itemHolder.update();
+        assertEquals(14, itemHolder.item.sellIn);
+        assertEquals(21, itemHolder.item.quality);
+    }
+
+    @Test
+    void backstage_passes_max_quality() {
+        ItemHolder itemHolder = ItemHolderFactory.createItemHolder(new Item("Backstage passes to a TAFKAL80ETC concert", 2, 50));
+        itemHolder.update();
+        assertEquals(1, itemHolder.item.sellIn);
+        assertEquals(50, itemHolder.item.quality);
+    }
+
+    @Test
+    void backstage_passes_day_ten() {
+        ItemHolder itemHolder = ItemHolderFactory.createItemHolder(new Item("Backstage passes to a TAFKAL80ETC concert", 10, 20));
+        itemHolder.update();
+        assertEquals(9, itemHolder.item.sellIn);
+        assertEquals(22, itemHolder.item.quality);
+    }
+
+    @Test
+    void backstage_passes_day_five() {
+        ItemHolder itemHolder = ItemHolderFactory.createItemHolder(new Item("Backstage passes to a TAFKAL80ETC concert", 5, 20));
+        itemHolder.update();
+        assertEquals(4, itemHolder.item.sellIn);
+        assertEquals(23, itemHolder.item.quality);
+    }
+
+    @Test
+    void backstage_passes_day_zero() {
+        ItemHolder itemHolder = ItemHolderFactory.createItemHolder(new Item("Backstage passes to a TAFKAL80ETC concert", 1, 20));
+        itemHolder.update();
+        assertEquals(0, itemHolder.item.sellIn);
+        assertEquals(23, itemHolder.item.quality);
+    }
+
+    @Test
+    void backstage_passes_expired() {
+        ItemHolder itemHolder = ItemHolderFactory.createItemHolder(new Item("Backstage passes to a TAFKAL80ETC concert", 0, 20));
+        itemHolder.update();
+        assertEquals(-1, itemHolder.item.sellIn);
+        assertEquals(0, itemHolder.item.quality);
+    }
+}