Add Conjured item to business logic

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

@@ -0,0 +1,19 @@
+package com.gildedrose;
+
+public class Conjured extends InventoryItem {
+    public Conjured(Item item) {
+        super(item);
+    }
+
+    @Override
+    void age() {
+        decreaseQuality();
+        decreaseSellIn();
+        if (item.sellIn < Constants.SELLIN_DAY) decreaseQuality();
+    }
+
+    @Override
+    protected void decreaseQuality() {
+        if (item.quality > Constants.MIN_QUALITY) item.quality -= 2;
+    }
+}

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

@@ -4,6 +4,7 @@ public final class Constants {
     public static final String BACKSTAGE = "Backstage passes to a TAFKAL80ETC concert";
     public static final String AGED_BRIE = "Aged Brie";
     public static final String SULFURAS = "Sulfuras, Hand of Ragnaros";
+    public static final String CONJURED = "Conjured Mana Cake";
     public static final int MAX_QUALITY = 50;
     public static final int MIN_QUALITY = 0;
     public static final int SELLIN_DAY = 0;

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

@@ -13,13 +13,14 @@ public class InventoryItem {
         if (item.name.equals(SULFURAS)) return new Sulfuras(item);
         if (item.name.equals(AGED_BRIE)) return new AgedBrie(item);
         if (item.name.equals(BACKSTAGE)) return new Backstage(item);
+        if (item.name.equals(CONJURED)) return new Conjured(item);
         return new InventoryItem(item);
     }
 
     void age() {
         decreaseQuality();
         decreaseSellIn();
-        if (item.sellIn < 0) decreaseQuality();
+        if (item.sellIn < Constants.SELLIN_DAY) decreaseQuality();
     }
 
     protected void decreaseSellIn() {
@@ -27,6 +28,6 @@ public class InventoryItem {
     }
 
     protected void decreaseQuality() {
-        if (item.quality > 0) item.quality--;
+        if (item.quality > Constants.MIN_QUALITY) item.quality--;
     }
 }

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

@@ -30,14 +30,14 @@ class GildedRoseTest {
 
     @Test
     void increaseAgedBrieQualityWhenItGetsOlder() {
-        Item[] items = new Item[]{new Item("Aged Brie", 0, 2)};
+        Item[] items = new Item[]{new Item(Constants.AGED_BRIE, 0, 2)};
         GildedRose.updateQuality(new GildedRose(items));
         assertEquals(4, items[0].quality);
     }
 
     @Test
     void neverMustHaveAnItemWithMoreThan50OfQuality() {
-        Item[] items = new Item[]{new Item("Aged Brie", 0, 50)};
+        Item[] items = new Item[]{new Item(Constants.AGED_BRIE, 0, 50)};
         GildedRose.updateQuality(new GildedRose(items));
         assertEquals(50, items[0].quality);
     }
@@ -45,26 +45,33 @@ class GildedRoseTest {
 
     @Test
     void neverModifySulfurasQuality() {
-        Item[] items = new Item[]{new Item("Sulfuras, Hand of Ragnaros", 0, 50)};
+        Item[] items = new Item[]{new Item(Constants.SULFURAS, 0, 50)};
         GildedRose.updateQuality(new GildedRose(items));
         assertEquals(50, items[0].quality);
     }
 
     @Test
     void neverModifySulfurasQualityEvenISGreaterThan50() {
-        Item[] items = new Item[]{new Item("Sulfuras, Hand of Ragnaros", 0, 80)};
+        Item[] items = new Item[]{new Item(Constants.SULFURAS, 0, 80)};
         GildedRose.updateQuality(new GildedRose(items));
         assertEquals(80, items[0].quality);
     }
 
     @Test
     void mustIncreaseBackstagePassesQualityWhenItsSellInApproaches() {
-        Item[] items = new Item[]{new Item("Backstage passes to a TAFKAL80ETC concert", 15, 20),
-            new Item("Backstage passes to a TAFKAL80ETC concert", 10, 20),
-            new Item("Backstage passes to a TAFKAL80ETC concert", 5, 20)};
+        Item[] items = new Item[]{new Item(Constants.BACKSTAGE, 15, 20),
+            new Item(Constants.BACKSTAGE, 10, 20),
+            new Item(Constants.BACKSTAGE, 5, 20)};
         GildedRose.updateQuality(new GildedRose(items));
         assertEquals(21, items[0].quality);
         assertEquals(22, items[1].quality);
         assertEquals(23, items[2].quality);
     }
+
+    @Test
+    void mustDecreaseQualityTwiceAsFastIfItemIsConjured() {
+        Item[] items = new Item[]{new Item(Constants.CONJURED, 0, 20)};
+        GildedRose.updateQuality(new GildedRose(items));
+        assertEquals(16, items[0].quality);
+    }
 }

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

@@ -19,7 +19,7 @@ class GoldenMasterApprovalTest {
     }
 
     private String[] itemTypes() {
-        return new String[]{"common item", "Aged Brie", "Backstage passes to a TAFKAL80ETC concert", "Sulfuras, Hand of Ragnaros"};
+        return new String[]{Constants.AGED_BRIE, Constants.BACKSTAGE, "Common item", Constants.CONJURED, Constants.SULFURAS};
     }
 
     private Integer[] sellInRangeValues() {