🔨 move validation logic

negative quality check to factory and legendary validation to validation
class

Java/src/main/java/com/gildedrose/item_helpers/ItemFactory.java

@@ -1,13 +1,12 @@
 package com.gildedrose.item_helpers;
 
-import com.gildedrose.main.Item;
 import com.gildedrose.items.AgedBrieItem;
 import com.gildedrose.items.BackstagePassItem;
 import com.gildedrose.items.ConjuredItem;
 import com.gildedrose.items.LegendaryItem;
 import com.gildedrose.items.NormalItem;
+import com.gildedrose.main.Item;
 
-import static com.gildedrose.item_helpers.ItemHandler.validate;
 import static com.gildedrose.item_helpers.ItemName.getItemName;
 
 public class ItemFactory {
@@ -16,7 +15,7 @@ public class ItemFactory {
     }
 
     public static ItemType getItem(Item item) {
-        validate(item);
+        validateQuality(item);
         ItemName itemName = getItemName(item.name);
         switch (itemName) {
             case AGED_BRIE:
@@ -32,4 +31,15 @@ public class ItemFactory {
         }
     }
 
+    public static final String QUALITY_ERROR_MESSAGE = "Quality cannot be negative! Current value: ";
+
+    private static void validateQuality(Item item) {
+        if (qualityIsNegative(item)) {
+            throw new IllegalArgumentException(QUALITY_ERROR_MESSAGE + item.quality);
+        }
+    }
+
+    private static boolean qualityIsNegative(Item item) {
+        return item.quality < 0;
+    }
 }

Java/src/main/java/com/gildedrose/item_helpers/ItemHandler.java

@@ -2,33 +2,16 @@ package com.gildedrose.item_helpers;
 
 import com.gildedrose.main.Item;
 
-import static com.gildedrose.items.LegendaryItem.NOT_LEGENDARY_ITEM_ERROR_MESSAGE;
-import static com.gildedrose.items.LegendaryItem.isNotLegendary;
 import static java.lang.Math.max;
 
 public class ItemHandler {
 
-    public static final String QUALITY_ERROR_MESSAGE = "Quality cannot be negative! Current value: ";
-
     private final Item item;
 
     public ItemHandler(Item item) {
         this.item = item;
     }
 
-    static void validate(Item item) {
-        if (qualityIsNegative(item)) {
-            throw new IllegalArgumentException(QUALITY_ERROR_MESSAGE + item.quality);
-        }
-        if (isNotLegendary(item)) {
-            throw new IllegalArgumentException(NOT_LEGENDARY_ITEM_ERROR_MESSAGE + item.quality);
-        }
-    }
-
-    private static boolean qualityIsNegative(Item item) {
-        return item.quality < 0;
-    }
-
     public boolean qualityIsHigherThanZero() {
         return item.quality > 0;
     }

Java/src/main/java/com/gildedrose/items/LegendaryItem.java

@@ -1,8 +1,8 @@
 package com.gildedrose.items;
 
-import com.gildedrose.main.Item;
 import com.gildedrose.item_helpers.ItemHandler;
 import com.gildedrose.item_helpers.ItemType;
+import com.gildedrose.main.Item;
 
 import static com.gildedrose.item_helpers.ItemName.LEGENDARY;
 
@@ -13,6 +13,7 @@ public class LegendaryItem implements ItemType {
     private final ItemHandler item;
 
     public LegendaryItem(Item item) {
+        validate(item);
         this.item = new ItemHandler(item);
     }
 
@@ -21,7 +22,13 @@ public class LegendaryItem implements ItemType {
         item.decrementSellInDate();
     }
 
-    public static boolean isNotLegendary(Item item) {
+    private void validate(Item item) {
+        if (notLegendary(item)) {
+            throw new IllegalArgumentException(NOT_LEGENDARY_ITEM_ERROR_MESSAGE + item.quality);
+        }
+    }
+
+    public boolean notLegendary(Item item) {
         return item.name.equals(LEGENDARY.toString()) && item.quality != LEGENDARY_ITEM_QUALITY;
     }
 

Java/src/test/java/com/gildedrose/items/TestHelper.java

@@ -3,7 +3,7 @@ package com.gildedrose.items;
 import com.gildedrose.main.GildedRose;
 import com.gildedrose.main.Item;
 
-import static com.gildedrose.item_helpers.ItemHandler.QUALITY_ERROR_MESSAGE;
+import static com.gildedrose.item_helpers.ItemFactory.QUALITY_ERROR_MESSAGE;
 import static org.junit.jupiter.api.Assertions.*;
 
 public class TestHelper {