proper refactor

now this i'm happy with. fixed a few bugs along the way.

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

@@ -1,29 +1,22 @@
 package com.gildedrose;
 
+import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.stream.Collectors;
 
 class GildedRose {
     Item[] items;
+    private final List<ItemWrapper> itemWrappers;
 
     public GildedRose(Item[] items) {
         this.items = items;
+        this.itemWrappers = new ArrayList<>(items.length);
+        Arrays.stream(items).forEach(item -> itemWrappers.add(new ItemWrapper(item)));
     }
 
     public void updateQuality() {
-        Arrays.stream(items).forEach(this::updateQuality);
-    }
-
-    public void updateQuality(Item item) {
-        if (item.name.equals("Aged Brie")) {
-            AgedBrieStrategy.INSTANCE.applyTo(item);
-        } else if (item.name.startsWith("Backstage passes")) {
-            BackstagePassesStrategy.INSTANCE.applyTo(item);
-        } else if (item.name.startsWith("Conjured")) {
-            ConjuredStrategy.INSTANCE.applyTo(item);
-        } else {
-            DefaultStrategy.INSTANCE.applyTo(item);
-        }
+        itemWrappers.forEach(ItemWrapper::updateQuality);
     }
 }

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

@@ -0,0 +1,32 @@
+package com.gildedrose;
+
+import com.gildedrose.strategies.AgedBrieStrategy;
+import com.gildedrose.strategies.BackstagePassesStrategy;
+import com.gildedrose.strategies.ConjuredStrategy;
+import com.gildedrose.strategies.DefaultStrategy;
+import com.gildedrose.strategies.QualityUpdateStrategy;
+import com.gildedrose.strategies.SulfurasStrategy;
+
+public class ItemWrapper {
+    private final Item item;
+    private final QualityUpdateStrategy strategy;
+
+    public ItemWrapper(Item item) {
+        this.item = item;
+        if (item.name.equals("Aged Brie")) {
+            strategy = AgedBrieStrategy.INSTANCE;
+        } else if (item.name.startsWith("Backstage passes")) {
+            strategy = BackstagePassesStrategy.INSTANCE;
+        } else if (item.name.startsWith("Conjured")) {
+            strategy = ConjuredStrategy.INSTANCE;
+        } else if (item.name.startsWith("Sulfuras")) {
+            strategy = SulfurasStrategy.INSTANCE;
+        } else {
+            strategy = DefaultStrategy.INSTANCE;
+        }
+    }
+
+    public void updateQuality() {
+        strategy.applyTo(item);
+    }
+}

Java/src/main/java/com/gildedrose/strategies/AgedBrieStrategy.java

@@ -1,11 +1,13 @@
-package com.gildedrose;
+package com.gildedrose.strategies;
+
+import com.gildedrose.Item;
 
 public enum AgedBrieStrategy implements QualityUpdateStrategy {
     INSTANCE;
 
     @Override
     public void applyTo(Item item) {
-        item.quality = Math.min(50, item.sellIn < 0 ? item.quality+2 : item.quality+1);
+        item.quality = Math.min(50, item.sellIn <= 0 ? item.quality+2 : item.quality+1);
         --item.sellIn;
     }
 }

Java/src/main/java/com/gildedrose/strategies/BackstagePassesStrategy.java

@@ -1,4 +1,6 @@
-package com.gildedrose;
+package com.gildedrose.strategies;
+
+import com.gildedrose.Item;
 
 public enum BackstagePassesStrategy implements QualityUpdateStrategy {
     INSTANCE;
@@ -7,9 +9,9 @@ public enum BackstagePassesStrategy implements QualityUpdateStrategy {
     public void applyTo(Item item) {
         if (item.sellIn <= 0) {
             item.quality = 0;
-        } else if (item.sellIn >= 10) {
+        } else if (item.sellIn > 10) {
             item.quality = Math.min(50, item.quality+1);
-        } else if (item.sellIn >= 5) {
+        } else if (item.sellIn > 5) {
             item.quality = Math.min(50, item.quality+2);
         } else {
             item.quality = Math.min(50, item.quality+3);

Java/src/main/java/com/gildedrose/strategies/ConjuredStrategy.java

@@ -1,4 +1,6 @@
-package com.gildedrose;
+package com.gildedrose.strategies;
+
+import com.gildedrose.Item;
 
 public enum ConjuredStrategy implements QualityUpdateStrategy {
     INSTANCE;

Java/src/main/java/com/gildedrose/strategies/DefaultStrategy.java

@@ -1,4 +1,6 @@
-package com.gildedrose;
+package com.gildedrose.strategies;
+
+import com.gildedrose.Item;
 
 public enum DefaultStrategy implements QualityUpdateStrategy {
     INSTANCE;
@@ -6,6 +8,6 @@ public enum DefaultStrategy implements QualityUpdateStrategy {
     @Override
     public void applyTo(Item item) {
         item.quality = Math.max(0, item.sellIn > 0 ? (item.quality-1) : (item.quality-2));
-        item.sellIn = item.sellIn - 1;
+        --item.sellIn;
     }
 }

Java/src/main/java/com/gildedrose/strategies/QualityUpdateStrategy.java

@@ -1,4 +1,6 @@
-package com.gildedrose;
+package com.gildedrose.strategies;
+
+import com.gildedrose.Item;
 
 public interface QualityUpdateStrategy {
     void applyTo(Item item);

Java/src/main/java/com/gildedrose/strategies/SulfurasStrategy.java

@@ -0,0 +1,12 @@
+package com.gildedrose.strategies;
+
+import com.gildedrose.Item;
+
+public enum SulfurasStrategy implements QualityUpdateStrategy{
+    INSTANCE;
+
+    @Override
+    public void applyTo(Item item) {
+        //do nothing
+    }
+}

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

@@ -108,7 +108,6 @@ class GildedRoseTest {
     }
 
     @Test
-    @Disabled
     @DisplayName("Conjured Item")
     void updateQualityConjuredItem() {
         Item conjuredItemUnderTest = new Item("Conjured Sample Item", 1, 8);