Sulfuras, being a legendary item, never has to be sold or decreases in Quality

Java/README.md

@@ -14,7 +14,7 @@
 -[x] The Quality of an item is never negative
 -[x] "Aged Brie" actually increases in Quality the older it gets
 -[x] The Quality of an item is never more than 50
--[ ] "Sulfuras", being a legendary item, never has to be sold or decreases in Quality
+-[x] "Sulfuras", being a legendary item, never has to be sold or decreases in Quality
 -[ ] "Backstage passes", like aged brie, increases in Quality as its SellIn value approaches;
 -[ ] Quality increases by 2 when there are 10 days or less and by 3 when there are 5 days or less but
 -[ ] Quality drops to 0 after the concert

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

@@ -88,4 +88,22 @@ public class GildedRoseTest {
         assertEquals(50, app.items[0].quality);
     }
 
+    //Sulfuras, Hand of Ragnaros
+    @Test
+    @DisplayName("\"Sulfuras\", being a legendary item, never has to be sold or decreases in Quality")
+    public void should(){
+        Item[] items = new Item[]{TestHelper.getItem("Sulfuras, Hand of Ragnaros", 0, 10)};
+        GildedRose app = new GildedRose(items);
+
+        //day 1, don't impact quality
+        app.updateQuality();
+        assertEquals(10, app.items[0].quality);
+        assertEquals(0, app.items[0].sellIn);
+
+        //day 0, don't impact quality
+        app.updateQuality();
+        assertEquals(10, app.items[0].quality);
+        assertEquals(0, app.items[0].sellIn);
+    }
+
 }