Refactored Code : Moved implementation of expired items quality update to specific classes.

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

@@ -8,6 +8,14 @@ public class AgedBrie implements Goods {
 		addQualityWhenWithInLimit(item);
 
 	}
+	
+	@Override
+	public void updateQualityForExpiredItem(Item item) {
+		if (item.sellIn < 0) {
+			addQualityWhenWithInLimit(item);
+		}
+
+	}
 
 	private void addQualityWhenWithInLimit(Item item) {
 		if (item.quality < MAX_ALLOWED_QUALITY) {

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

@@ -5,6 +5,7 @@ public class BackStagePasses implements Goods {
 	private static final int MAX_ALLOWED_QUALITY = 50;
 	private static final int SELL_IN_MAX_THRESHOLD_DAY = 11;
 	private static final int SELL_IN_MIN_THRESHOLD_DAY = 6;
+	private static final int ZERO = 0;
 
 	@Override
 	public void updateQuality(Item item) {
@@ -22,4 +23,11 @@ public class BackStagePasses implements Goods {
 			item.quality++;
 		}
 	}
+
+	@Override
+	public void updateQualityForExpiredItem(Item item) {
+		if (item.sellIn < 0) {
+			item.quality = ZERO;
+		}
+	}
 }

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

@@ -7,4 +7,11 @@ public class Generic implements Goods {
 			item.quality--;
 		}
 	}
+
+	@Override
+	public void updateQualityForExpiredItem(Item item) {
+		if (item.sellIn < 0 && item.quality > 0) {
+			item.quality--;
+		}
+	}
 }

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

@@ -9,47 +9,13 @@ class GildedRose {
         this.items = items;
     }
 
-    public void updateQuality() {
+	public void updateQuality() {
 		for (Item item : items) {
 			Goods goods = GoodsFactory.getGoods(item.name);
 			goods.updateQuality(item);
 			goods.updateSellInDays(item);
-
-            updateQualityForExpiredItem(item);
-        }
-    }
-
-
-	private void addQualityWhenWithInLimit(Item item) {
-		if (item.quality < 50) {
-		    item.quality = item.quality + 1;
+			goods.updateQualityForExpiredItem(item);
 		}
 	}
 
-	private void updateQualityForExpiredItem(Item item) {
-		if (item.sellIn < 0) {
-		    if (!item.name.equals("Aged Brie")) {
-		        if (!item.name.equals("Backstage passes to a TAFKAL80ETC concert")) {
-		            if (item.quality > 0) {
-		                if (!item.name.equals("Sulfuras, Hand of Ragnaros")) {
-		                    updateQualityForExpiredItemNormal(item);
-		                }
-		            }
-		        } else {
-		            updateQualityForExpiredItemBackstagePasses(item);
-		        }
-		    } else {
-		        addQualityWhenWithInLimit(item);
-		    }
-		}
-	}
-
-	private void updateQualityForExpiredItemBackstagePasses(Item item) {
-		item.quality = 0;
-	}
-
-	private void updateQualityForExpiredItemNormal(Item item) {
-		item.quality--;
-	}
-    
 }

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

@@ -7,4 +7,6 @@ public interface Goods {
 	default void updateSellInDays(Item item) {
 		item.sellIn--;
 	}
+	
+	public void updateQualityForExpiredItem(Item item);
 }

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

@@ -15,4 +15,10 @@ public class Sulfuras implements Goods {
 		// decreases in quality.
 	}
 
+	@Override
+	public void updateQualityForExpiredItem(Item item) {
+		// Do nothing because Sulfuras being a legendary item, never has to be sold or
+		// decreases in quality.		
+	}
+
 }

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

@@ -23,6 +23,13 @@ class AgedBrieTest {
 				Arguments.of(new Item(GoodsType.AGED_BRIE.getGoodsName(), 1, 50), 0)
 				);
 	}
+	
+	private static Stream<Arguments> getTestExpiredItemsWithExpectedQuality() {
+		return Stream.of(
+				Arguments.of(new Item(GoodsType.AGED_BRIE.getGoodsName(), -1, 2), 3), 
+				Arguments.of(new Item(GoodsType.AGED_BRIE.getGoodsName(), 1, 2), 2)
+				);
+	}
 
 
 	@ParameterizedTest(name = "Test updateQuality - {index}")
@@ -41,5 +48,13 @@ class AgedBrieTest {
 		assertEquals(expectedSellin, item.sellIn);
 
 	}
+	
+	@ParameterizedTest(name = "Test updateQuality for expired items - {index}")
+	@MethodSource("getTestExpiredItemsWithExpectedQuality")
+	void testtestUpdateQualityForExpiredItems(Item item, int expectedQuality) {
+		AgedBrie agedBrie = new AgedBrie();
+		agedBrie.updateQualityForExpiredItem(item);
+		assertEquals(expectedQuality, item.quality);
+	}
 
 }

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

@@ -24,6 +24,12 @@ class BackStagePassesTest {
 				Arguments.of(new Item(GoodsType.BACK_STAGE_PASSES.getGoodsName(), 1, 50), 0)
 				);
 	}
+	
+	private static Stream<Arguments> getTestExpiredItemsWithExpectedQuality() {
+		return Stream.of(
+				Arguments.of(new Item(GoodsType.BACK_STAGE_PASSES.getGoodsName(), -1, 2), 0),
+				Arguments.of(new Item(GoodsType.BACK_STAGE_PASSES.getGoodsName(), 1, 2), 2));
+	}
 
 
 
@@ -33,7 +39,6 @@ class BackStagePassesTest {
 		BackStagePasses backStagePasses = new BackStagePasses();
 		backStagePasses.updateQuality(item);
 		assertEquals(expectedQuality, item.quality);
-
 	}
 
 	@ParameterizedTest(name = "Test updateSellIn - {index}")
@@ -42,7 +47,14 @@ class BackStagePassesTest {
 		BackStagePasses backStagePasses = new BackStagePasses();
 		backStagePasses.updateSellInDays(item);
 		assertEquals(expectedSellin, item.sellIn);
-
+	}
+	
+	@ParameterizedTest(name = "Test updateQuality for expired items - {index}")
+	@MethodSource("getTestExpiredItemsWithExpectedQuality")
+	void testUpdateQualityForExpiredItems(Item item, int expectedQuality) {
+		BackStagePasses backStagePasses = new BackStagePasses();
+		backStagePasses.updateQualityForExpiredItem(item);
+		assertEquals(expectedQuality, item.quality);
 	}
 
 }

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

@@ -23,6 +23,14 @@ class GenericTest {
 				Arguments.of(new Item("Generic Item", 2, 2), 1)
 				);
 	}
+	
+	private static Stream<Arguments> getTestExpiredItemsWithExpectedQuality() {
+		return Stream.of(
+				Arguments.of(new Item("Generic Item", -1, 1), 0), 
+				Arguments.of(new Item("Generic Item", 0, 2), 2),
+				Arguments.of(new Item("Generic Item", -1, -1), -1)
+				);
+	}
 
 
 
@@ -32,7 +40,6 @@ class GenericTest {
 		Generic generic = new Generic();
 		generic.updateQuality(item);
 		assertEquals(expectedQuality, item.quality);
-
 	}
 
 	@ParameterizedTest(name = "Test updateSellIn - {index}")
@@ -42,5 +49,13 @@ class GenericTest {
 		generic.updateSellInDays(item);
 		assertEquals(expectedSellin, item.sellIn);
 	}
+	
+	@ParameterizedTest(name = "Test updateQuality for expired items- {index}")
+	@MethodSource("getTestExpiredItemsWithExpectedQuality")
+	void testUpdateQualityForExpiredItems(Item item, int expectedQuality) {
+		Generic generic = new Generic();
+		generic.updateQualityForExpiredItem(item);
+		assertEquals(expectedQuality, item.quality);
+	}
 
 }

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

@@ -45,7 +45,10 @@ class GildedRoseTest {
 
 				Arguments.of(new Item[] { new Item("Coffee Day", 1, 1) }, 0),
 				Arguments.of(new Item[] { new Item("Coffee Day", -1, 1) }, 0),
-				Arguments.of(new Item[] { new Item("Coffee Day", -1, 2) }, 0)
+				Arguments.of(new Item[] { new Item("Coffee Day", -1, 2) }, 0),
+				
+				Arguments.of(new Item[] { new Item(GoodsType.SULFURAS.getGoodsName(), -1, 10) }, 10),
+				Arguments.of(new Item[] { new Item(GoodsType.SULFURAS.getGoodsName(), 1, 10) }, 10)
 
 		);
 	}

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

@@ -21,6 +21,13 @@ class SulfurasTest {
 				Arguments.of(new Item(GoodsType.SULFURAS.getGoodsName(), 2, 2), 2),
 				Arguments.of(new Item(GoodsType.SULFURAS.getGoodsName(), 1, 50), 1));
 	}
+	
+	private static Stream<Arguments> getTestExpiredItemsWithExpectedQuality() {
+		return Stream.of(
+				Arguments.of(new Item(GoodsType.SULFURAS.getGoodsName(), -1, 2), 2),
+				Arguments.of(new Item(GoodsType.SULFURAS.getGoodsName(), -1, 50), 50)
+				);
+	}
 
 	@ParameterizedTest(name = "Test updateQuality - {index}")
 	@MethodSource("getTestItemsWithExpectedQuality")
@@ -37,5 +44,14 @@ class SulfurasTest {
 		sulfurus.updateSellInDays(item);
 		assertEquals(expectedSellin, item.sellIn);
 	}
+	
+	@ParameterizedTest(name = "Test updateQuality for expired items- {index}")
+	@MethodSource("getTestExpiredItemsWithExpectedQuality")
+	void testUpdateQualityForExpiredItems(Item item, int expectedQuality) {
+		Sulfuras sulfurus = new Sulfuras();
+		sulfurus.updateQualityForExpiredItem(item);
+		assertEquals(expectedQuality, item.quality);
+	}
+
 
 }