feat: conjured-items - Refactored the code to use the strategies.

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

@@ -1,14 +0,0 @@
-package com.gildedrose;
-
-public class AgedBrieItemStrategyImpl implements ItemStrategy {
-    @Override
-    public void updateQuality(Item item) {
-        if (item.quality < 50) {
-            item.quality = item.quality + 1;
-        }
-        item.sellIn = item.sellIn - 1;
-        if (item.sellIn < 0) {
-            item.quality = item.quality < 50 ? item.quality + 1 : 50;
-        }
-    }
-}

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

@@ -1,26 +0,0 @@
-package com.gildedrose;
-
-public class BackStageItemStrategyImpl implements ItemStrategy {
-    @Override
-    public void updateQuality(Item item) {
-        if (item.quality < 50) {
-            item.quality = item.quality + 1;
-            if (item.sellIn < 11) {
-                if (item.quality < 50) {
-                    item.quality = item.quality + 1;
-                }
-            }
-
-            if (item.sellIn < 6) {
-                if (item.quality < 50) {
-                    item.quality = item.quality + 1;
-                }
-            }
-        }
-        item.sellIn = item.sellIn - 1;
-
-        if (item.sellIn < 0) {
-            item.quality = 0;
-        }
-    }
-}

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

@@ -1,9 +0,0 @@
-package com.gildedrose;
-
-public class ConjuredItemStrategyImpl implements ItemStrategy {
-    @Override
-    public void updateQuality(Item item) {
-        item.quality = item.quality > 2 ? item.quality - 2 : 0;
-        item.sellIn = item.sellIn - 1;
-    }
-}

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

@@ -1,62 +1,61 @@
 package com.gildedrose;
 
+import com.gildedrose.strategy.AgedBrieItemStrategyImpl;
+import com.gildedrose.strategy.BackStageItemStrategyImpl;
+import com.gildedrose.strategy.ConjuredItemStrategyImpl;
+import com.gildedrose.strategy.ItemStrategy;
+import com.gildedrose.strategy.SulfurasItemStrategyImpl;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.TreeMap;
+
 class GildedRose {
-    Item[] items;
+  private static final ItemStrategy DEFAULT_STRATEGY = new ItemStrategy() {
+  };
+  private static final Map<String, ItemStrategy> STRATEGIES = new TreeMap<>();
+
+  static final String AGED_BRIE = "Aged Brie";
+  static final String CONJURED = "Conjured Mana Cake";
+  static final String DEXTERITY_VEST = "+5 Dexterity Vest";
+  static final String SULFURAS = "Sulfuras, Hand of Ragnaros";
+  static final String ELIXIR_OF_THE_MONGOOSE = "Elixir of the Mongoose";
+  static final String BACKSTAGE_PASSES = "Backstage passes to a TAFKAL80ETC concert";
+
+  private static final List<String> KNOWN_ITEM_NAMES =
+      List.of(AGED_BRIE, CONJURED, DEXTERITY_VEST, SULFURAS, ELIXIR_OF_THE_MONGOOSE,
+          BACKSTAGE_PASSES);
+
+  static {
+    STRATEGIES.put(DEXTERITY_VEST, DEFAULT_STRATEGY);
+    STRATEGIES.put(ELIXIR_OF_THE_MONGOOSE, DEFAULT_STRATEGY);
+    STRATEGIES.put(AGED_BRIE, new AgedBrieItemStrategyImpl());
+    STRATEGIES.put(CONJURED, new ConjuredItemStrategyImpl());
+    STRATEGIES.put(SULFURAS, new SulfurasItemStrategyImpl());
+    STRATEGIES.put(BACKSTAGE_PASSES, new BackStageItemStrategyImpl());
+  }
+
+  private final Item[] items;
 
   public GildedRose(Item[] items) {
+    if (items == null || items.length == 0) {
+      throw new IllegalArgumentException("Items cannot be empty");
+    }
     this.items = items;
   }
 
   public void updateQuality() {
-        for (int i = 0; i < items.length; i++) {
+    Arrays.stream(items).forEach(item -> findStrategy(item).updateQuality(item));
-            if (!items[i].name.equals("Aged Brie")
-                    && !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) {
+  private ItemStrategy findStrategy(Item item) {
-                            if (items[i].quality < 50) {
+    if (KNOWN_ITEM_NAMES.contains(item.name)) {
-                                items[i].quality = items[i].quality + 1;
+      return STRATEGIES.get(item.name);
-                            }
-                        }
-                    }
     }
+    return DEFAULT_STRATEGY;
   }
 
-            if (!items[i].name.equals("Sulfuras, Hand of Ragnaros")) {
+  public Item[] getItems() {
-                items[i].sellIn = items[i].sellIn - 1;
+    return items;
-            }
-
-            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/ItemStrategy.java

@@ -1,13 +0,0 @@
-package com.gildedrose;
-
-public interface ItemStrategy {
-    default void updateQuality(Item item) {
-        if (item.quality > 0) {
-            item.quality = item.quality - 1;
-        }
-        item.sellIn = item.sellIn - 1;
-        if (item.sellIn < 0 && item.quality > 0) {
-            item.quality = item.quality - 1;
-        }
-    }
-}

Java/src/main/java/com/gildedrose/strategy/AgedBrieItemStrategyImpl.java

@@ -0,0 +1,12 @@
+package com.gildedrose.strategy;
+
+import com.gildedrose.Item;
+
+public class AgedBrieItemStrategyImpl implements ItemStrategy {
+    @Override
+    public void updateQuality(Item item) {
+        item.sellIn--;
+        int increment = item.sellIn < 0 ? 2 * INCREASE_RATE : INCREASE_RATE;
+        increaseQuality(item, increment);
+    }
+}

Java/src/main/java/com/gildedrose/strategy/BackStageItemStrategyImpl.java

@@ -0,0 +1,24 @@
+package com.gildedrose.strategy;
+
+import com.gildedrose.Item;
+
+public class BackStageItemStrategyImpl implements ItemStrategy {
+    @Override
+    public void updateQuality(Item item) {
+        item.sellIn--;
+
+        if (item.sellIn < 0) {
+            item.quality = 0;
+            return;
+        }
+
+        int increment = INCREASE_RATE;
+        if (item.sellIn < 5) {
+            increment += 2;
+        } else if (item.sellIn < 10) {
+            increment++;
+        }
+
+        increaseQuality(item, increment);
+    }
+}

Java/src/main/java/com/gildedrose/strategy/ConjuredItemStrategyImpl.java

@@ -0,0 +1,12 @@
+package com.gildedrose.strategy;
+
+import com.gildedrose.Item;
+
+public class ConjuredItemStrategyImpl implements ItemStrategy {
+    @Override
+    public void updateQuality(Item item) {
+        item.sellIn--;
+        int decrement = item.sellIn < 0 ? 4 * DEGRADATION_RATE : 2 * DEGRADATION_RATE;
+        decreaseQuality(item, decrement);
+    }
+}

Java/src/main/java/com/gildedrose/strategy/ItemStrategy.java

@@ -0,0 +1,24 @@
+package com.gildedrose.strategy;
+
+import com.gildedrose.Item;
+
+public interface ItemStrategy {
+    int MINIMUM_QUALITY = 0;
+    int MAXIMUM_QUALITY = 50;
+    int DEGRADATION_RATE = 1;
+    int INCREASE_RATE = 1;
+
+    default void updateQuality(Item item) {
+        item.sellIn--;
+        int decrement = item.sellIn < 0 ? 2 * DEGRADATION_RATE : DEGRADATION_RATE;
+        decreaseQuality(item, decrement);
+    }
+
+    default void increaseQuality(Item item, int amount) {
+        item.quality = Math.min(MAXIMUM_QUALITY, item.quality + amount);
+    }
+
+    default void decreaseQuality(Item item, int amount) {
+        item.quality = Math.max(MINIMUM_QUALITY, item.quality - amount);
+    }
+}

Java/src/main/java/com/gildedrose/strategy/SulfurasItemStrategyImpl.java

@@ -1,8 +1,10 @@
-package com.gildedrose;
+package com.gildedrose.strategy;
+
+import com.gildedrose.Item;
 
 public class SulfurasItemStrategyImpl implements ItemStrategy {
     @Override
     public void updateQuality(Item item) {
-        // Quality remains intact. Not for sel!
+        // Quality remains unchanged. Not for sale!
     }
 }

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

@@ -1,17 +1,15 @@
 package com.gildedrose;
 
-import org.junit.jupiter.api.Test;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
-class GildedRoseTest {
+import org.junit.jupiter.api.Test;
 
+class GildedRoseTest {
     @Test
-    void foo() {
+    void test() {
-        Item[] items = new Item[] { new Item("foo", 0, 0) };
+        Item[] items = new Item[] {new Item("foo", 0, 0)};
         GildedRose app = new GildedRose(items);
         app.updateQuality();
-        assertEquals("fixme", app.items[0].name);
+        assertEquals("foo", app.getItems()[0].name);
     }
-
 }

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

@@ -5,16 +5,16 @@ public class TexttestFixture {
         System.out.println("OMGHAI!");
 
         Item[] items = new Item[] {
-                new Item("+5 Dexterity Vest", 10, 20), //
+            new Item(GildedRose.DEXTERITY_VEST, 10, 20), //
-                new Item("Aged Brie", 2, 0), //
+            new Item(GildedRose.AGED_BRIE, 2, 0), //
-                new Item("Elixir of the Mongoose", 5, 7), //
+            new Item(GildedRose.ELIXIR_OF_THE_MONGOOSE, 5, 7), //
-                new Item("Sulfuras, Hand of Ragnaros", 0, 80), //
+            new Item(GildedRose.SULFURAS, 0, 80), //
-                new Item("Sulfuras, Hand of Ragnaros", -1, 80),
+            new Item(GildedRose.SULFURAS, -1, 80),
-                new Item("Backstage passes to a TAFKAL80ETC concert", 15, 20),
+            new Item(GildedRose.BACKSTAGE_PASSES, 15, 20),
-                new Item("Backstage passes to a TAFKAL80ETC concert", 10, 49),
+            new Item(GildedRose.BACKSTAGE_PASSES, 10, 49),
-                new Item("Backstage passes to a TAFKAL80ETC concert", 5, 49),
+            new Item(GildedRose.BACKSTAGE_PASSES, 5, 49),
             // this conjured item does not work properly yet
-                new Item("Conjured Mana Cake", 3, 6) };
+            new Item(GildedRose.CONJURED, 3, 6)};
 
         GildedRose app = new GildedRose(items);
 
@@ -33,5 +33,4 @@ public class TexttestFixture {
             app.updateQuality();
         }
     }
-
 }