introduces Template Pattern with abstract class CustomisedItem

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

@@ -1,9 +1,7 @@
 package com.gildedrose;
 
-import com.gildedrose.item.CustomisedItem;
 import com.gildedrose.item.Item;
 import com.gildedrose.item.CustomisedItemFactory;
-import com.gildedrose.item.QualityValues;
 
 class GildedRose {
 
@@ -17,20 +15,7 @@ class GildedRose {
 
     public void updateQuality() {
         for (Item item : items) {
-            itemFactory.customiseItem(item).updateState();
-            if (hasReachedLowestQualityValue(item)) {
-                item.quality = QualityValues.lowestValuePossible();
-            } else if (hasReachedHighestQualityValue(item)) {
-                item.quality = QualityValues.highestValuePossible(item);
-            }
+            itemFactory.customiseItem(item).updateState(item);
         }
     }
-
-    private boolean hasReachedLowestQualityValue(Item item) {
-        return item.quality < QualityValues.lowestValuePossible();
-    }
-
-    private boolean hasReachedHighestQualityValue(Item item) {
-        return item.quality > QualityValues.highestValuePossible(item);
-    }
 }

Java/src/main/java/com/gildedrose/item/AgedBrie.java

@@ -1,6 +1,6 @@
 package com.gildedrose.item;
 
-public class AgedBrie implements CustomisedItem {
+public class AgedBrie extends CustomisedItem {
 
     private final Item item;
 
@@ -8,16 +8,23 @@ public class AgedBrie implements CustomisedItem {
         this.item = item;
     }
 
-    public void updateState() {
-        decreaseSellByDayValueByOne();
-        increaseQualityByOne();
+    @Override
+    int updatedItemSellIn() {
+        return item.sellIn -= 1;
     }
 
-    private void decreaseSellByDayValueByOne() {
-        item.sellIn -= 1;
+    @Override
+    int updatedItemQuality() {
+        return item.quality += 1;
     }
 
-    private void increaseQualityByOne() {
-        item.quality += 1;
+    @Override
+    protected boolean hasReachedHighestQualityValue() {
+        return item.quality > QualityValues.highestValuePossible(item);
+    }
+
+    @Override
+    protected boolean hasReachedLowestQualityValue() {
+        return item.quality < QualityValues.lowestValuePossible();
     }
 }

Java/src/main/java/com/gildedrose/item/BackstagePassesItem.java

@@ -1,6 +1,6 @@
 package com.gildedrose.item;
 
-public class BackstagePassesItem implements CustomisedItem {
+public class BackstagePassesItem extends CustomisedItem {
 
     private final Item item;
 
@@ -8,32 +8,43 @@ public class BackstagePassesItem implements CustomisedItem {
         this.item = item;
     }
 
-    public void updateState() {
-        decreaseSellByDayValueByOne();
+    @Override
+    int updatedItemSellIn() {
+        return item.sellIn -= 1;
+    }
+
+    @Override
+    int updatedItemQuality() {
         if (sellByDayValueIsOver(10)) {
-            increaseQualityBy(1);
+            return qualityIncreasedBy(1);
         } else if (sellByDayValueIsOver(5)) {
-            increaseQualityBy(2);
+            return qualityIncreasedBy(2);
         } else if (sellByDayValueIsOver(0)) {
-            increaseQualityBy(3);
+            return qualityIncreasedBy(3);
         } else {
-            dropQualityToZero();
+            return qualityDroppedToZero();
         }
     }
 
-    private void decreaseSellByDayValueByOne() {
-        item.sellIn -= 1;
+    @Override
+    protected boolean hasReachedHighestQualityValue() {
+        return item.quality > QualityValues.highestValuePossible(item);
+    }
+
+    @Override
+    protected boolean hasReachedLowestQualityValue() {
+        return item.quality < QualityValues.lowestValuePossible();
     }
 
     private boolean sellByDayValueIsOver(int dayNumber) {
         return item.sellIn > dayNumber;
     }
 
-    private void increaseQualityBy(int qualityValue) {
-        item.quality += qualityValue;
+    private int qualityIncreasedBy(int qualityValue) {
+        return item.quality += qualityValue;
     }
 
-    private void dropQualityToZero() {
-        item.quality = 0;
+    private int qualityDroppedToZero() {
+        return 0;
     }
 }

Java/src/main/java/com/gildedrose/item/ConjuredItem.java

@@ -1,13 +1,38 @@
 package com.gildedrose.item;
 
-public class ConjuredItem extends StandardItem {
+public class ConjuredItem extends CustomisedItem {
+
+    private final Item item;
 
     public ConjuredItem(Item item) {
-        super(item);
+        this.item = item;
     }
 
     @Override
-    public int decreasingValueOverZeroDaysToSell() {
-        return 2;
+    protected boolean hasReachedHighestQualityValue() {
+        return item.quality > QualityValues.highestValuePossible(item);
+    }
+
+    @Override
+    protected boolean hasReachedLowestQualityValue() {
+        return item.quality < QualityValues.lowestValuePossible();
+    }
+
+    @Override
+    int updatedItemSellIn() {
+        return item.sellIn -= 1;
+    }
+
+    @Override
+    int updatedItemQuality() {
+        if (sellByDayValueIsOverZero()) {
+            return item.quality -= 2;
+        } else {
+            return item.quality -= 4;
+        }
+    }
+
+    private boolean sellByDayValueIsOverZero() {
+        return item.sellIn > 0;
     }
 }

Java/src/main/java/com/gildedrose/item/CustomisedItem.java

@@ -1,5 +1,23 @@
 package com.gildedrose.item;
 
-public interface CustomisedItem {
-    void updateState();
+public abstract class CustomisedItem {
+
+    public final void updateState(Item item) {
+        item.sellIn = updatedItemSellIn();
+        item.quality = updatedItemQuality();
+
+        if (hasReachedLowestQualityValue()) {
+            item.quality = QualityValues.lowestValuePossible();
+        } else if (hasReachedHighestQualityValue()) {
+            item.quality = QualityValues.highestValuePossible(item);
+        }
+    }
+
+    abstract int updatedItemSellIn();
+
+    abstract int updatedItemQuality();
+
+    protected abstract boolean hasReachedHighestQualityValue();
+
+    protected abstract boolean hasReachedLowestQualityValue();
 }

Java/src/main/java/com/gildedrose/item/CustomisedItemFactory.java

@@ -13,7 +13,7 @@ public class CustomisedItemFactory {
     public final static String CONJURED_ITEM = "Conjured";
 
     public CustomisedItemFactory() {
-        ITEM_TYPES_LIST.put(SULFURAS, (item) ->  new Sulfuras());
+        ITEM_TYPES_LIST.put(SULFURAS, Sulfuras::new);
         ITEM_TYPES_LIST.put(BRIE, AgedBrie::new);
         ITEM_TYPES_LIST.put(BACKSTAGE_PASSES_ITEM, BackstagePassesItem::new);
         ITEM_TYPES_LIST.put(CONJURED_ITEM, ConjuredItem::new);

Java/src/main/java/com/gildedrose/item/StandardItem.java

@@ -1,6 +1,6 @@
 package com.gildedrose.item;
 
-public class StandardItem implements CustomisedItem {
+public class StandardItem extends CustomisedItem {
 
     private final Item item;
 
@@ -8,32 +8,31 @@ public class StandardItem implements CustomisedItem {
         this.item = item;
     }
 
-    public void updateState() {
-        decreaseSellByDayValueByOne();
+    @Override
+    int updatedItemSellIn() {
+        return item.sellIn -= 1;
+    }
+
+    @Override
+    int updatedItemQuality() {
         if (sellByDayValueIsOverZero()) {
-            decreaseQualityBy(decreasingValueOverZeroDaysToSell());
+            return item.quality -= 1;
         } else {
-            decreaseQualityBy(decreasingValueForZeroOrLessDaysToSell());
+            return item.quality -= 2;
         }
     }
 
-    public int decreasingValueOverZeroDaysToSell() {
-        return 1;
+    @Override
+    protected boolean hasReachedHighestQualityValue() {
+        return item.quality > QualityValues.highestValuePossible(item);
     }
 
-    private void decreaseSellByDayValueByOne() {
-        item.sellIn -= 1;
+    @Override
+    protected boolean hasReachedLowestQualityValue() {
+        return item.quality < QualityValues.lowestValuePossible();
     }
 
     private boolean sellByDayValueIsOverZero() {
         return item.sellIn > 0;
     }
-
-    private void decreaseQualityBy(int qualityValue) {
-        item.quality -= qualityValue;
-    }
-
-    private int decreasingValueForZeroOrLessDaysToSell() {
-        return decreasingValueOverZeroDaysToSell() * 2;
-    }
 }

Java/src/main/java/com/gildedrose/item/Sulfuras.java

@@ -1,7 +1,30 @@
 package com.gildedrose.item;
 
-public class Sulfuras implements CustomisedItem {
+public class Sulfuras extends CustomisedItem {
 
-    public void updateState() {
+    private final Item item;
+
+    public Sulfuras(Item item) {
+        this.item = item;
+    }
+
+    @Override
+    int updatedItemSellIn() {
+        return item.sellIn;
+    }
+
+    @Override
+    int updatedItemQuality() {
+        return item.quality;
+    }
+
+    @Override
+    protected boolean hasReachedHighestQualityValue() {
+        return item.quality > QualityValues.highestValuePossible(item) ;
+    }
+
+    @Override
+    protected boolean hasReachedLowestQualityValue() {
+        return item.quality < QualityValues.lowestValuePossible();
     }
 }

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

@@ -74,7 +74,7 @@ public class GildedRoseTest {
     }
 
     @Test
-    public void backstagePassesItemDecreasesQualityByOneIfSellByDayMoreThanEleven() {
+    public void backstagePassesItemIncreasesQualityByOneIfSellByDayMoreThanEleven() {
         GildedRose app = newGildedRose(CustomisedItemFactory.BACKSTAGE_PASSES_ITEM, 12, 1);
 
         app.updateQuality();
@@ -83,7 +83,7 @@ public class GildedRoseTest {
     }
 
     @Test
-    public void backstagePassesItemDecreasesQualityByTwoIfSellByDayIsMoreThanSix() {
+    public void backstagePassesItemIncreasesQualityByTwoIfSellByDayIsMoreThanSix() {
         GildedRose app = newGildedRose(CustomisedItemFactory.BACKSTAGE_PASSES_ITEM, 10, 1);
 
         app.updateQuality();
@@ -92,7 +92,7 @@ public class GildedRoseTest {
     }
 
     @Test
-    public void backstagePassesItemDecreasesQualityByThreeIfSellByDayIsMoreThanZero() {
+    public void backstagePassesItemIncreasesQualityByThreeIfSellByDayIsMoreThanZero() {
         GildedRose app = newGildedRose(CustomisedItemFactory.BACKSTAGE_PASSES_ITEM, 5, 1);
 
         app.updateQuality();