Refactroring completed: 4 methods extracted to update each item indivdaully. Additionally, unit test added to handle most and edge cases

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

@@ -1,62 +1,103 @@
 package com.gildedrose;
 
 class GildedRose {
+
+    private final String AGED_BRIE = "Aged Brie";
+    private final String BACKSTAGE_PASS = "Backstage passes to a TAFKAL80ETC concert";
+    private final String SULFURAS = "Sulfuras, Hand of Ragnaros";
+
     Item[] items;
 
     public GildedRose(Item[] items) {
         this.items = items;
     }
 
+
+    public void updateAgedBrie(Item item) {
+
+        // quality for any item can not exceed 50
+        if (item.quality < 50) {
+            item.quality = item.quality + 1; // age brie quality update
+
+
+        }
+        // update sell in date
+        item.sellIn = item.sellIn - 1;
+        // quality for age brie gets better as it ages past its sellIn
+        if (item.sellIn < 0 && item.quality < 50) {
+            item.quality = item.quality + 1; // age brie quality update
+        }
+    }
+
+    public void updateBackStage(Item item) {
+        // no items quality gets above 50
+        if (item.quality < 50) {
+            item.quality = item.quality + 1; // backstage quality update
+
+            // quality increases twice if 10 days to sellIn
+            if (item.sellIn < 11 && item.quality < 50) {
+                item.quality = item.quality + 1;
+            }
+            // quality increases by three if 5 days to sellIn
+            if (item.sellIn < 6 && item.quality < 50) {
+                item.quality = item.quality + 1;
+            }
+        }
+        // update sell in date for Backstage item
+        item.sellIn = item.sellIn - 1;
+        // quality drops to zero if it's past concert date
+        if (item.sellIn < 0) {
+            item.quality = item.quality - item.quality;
+        }
+    }
+
+    public void updateSulfuras(Item item) {
+        // Sulfuras is a legendary item
+        // nothing happens for the sulfuras Item
+    }
+
+    public void updateNormalItem(Item item) {
+
+        // normal item quality decreases by 1 every day
+        if (item.quality > 0) {
+            item.quality = item.quality - 1;
+        }
+
+        // update sell in date for Normal item
+        item.sellIn = item.sellIn - 1;
+
+        // quality drops twice if item is past sellIn Date
+        if (item.sellIn < 0 && item.quality > 0) {
+            item.quality = item.quality - 1;
+        }
+    }
+
     public void updateQuality() {
-        for (int i = 0; i < items.length; i++) {
+        for (Item item : this.items) {
-            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")) {
+            // only sulfuras don't sell
-                        if (items[i].sellIn < 11) {
+            // hence update sellin value for all items except sulfuras here
-                            if (items[i].quality < 50) {
+
-                                items[i].quality = items[i].quality + 1;
+            if (item.name != SULFURAS) {
-                            }
-                        }
 
-                        if (items[i].sellIn < 6) {
-                            if (items[i].quality < 50) {
-                                items[i].quality = items[i].quality + 1;
-                            }
-                        }
-                    }
-                }
             }
 
-            if (!items[i].name.equals("Sulfuras, Hand of Ragnaros")) {
+            switch (item.name) {
-                items[i].sellIn = items[i].sellIn - 1;
+                case AGED_BRIE:
-            }
+                    updateAgedBrie(item);
+                    continue;
 
-            if (items[i].sellIn < 0) {
+                case BACKSTAGE_PASS:
-                if (!items[i].name.equals("Aged Brie")) {
+                    updateBackStage(item);
-                    if (!items[i].name.equals("Backstage passes to a TAFKAL80ETC concert")) {
+                    continue;
-                        if (items[i].quality > 0) {
+                case SULFURAS:
-                            if (!items[i].name.equals("Sulfuras, Hand of Ragnaros")) {
+                    updateSulfuras(item);
-                                items[i].quality = items[i].quality - 1;
+                    continue;
-                            }
+                default:
-                        }
+                    updateNormalItem(item);
-                    } else {
+                    continue;
-                        items[i].quality = items[i].quality - items[i].quality;
-                    }
-                } else {
-                    if (items[i].quality < 50) {
-                        items[i].quality = items[i].quality + 1;
-                    }
-                }
             }
         }
     }
+
 }

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

@@ -1,17 +1,158 @@
 package com.gildedrose;
 
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.*;
 
 class GildedRoseTest {
+    private final String AGED_BRIE = "Aged Brie";
+    private final String BACKSTAGE = "Backstage passes to a TAFKAL80ETC concert";
+    private final String SULFURAS = "Sulfuras, Hand of Ragnaros";
+    private final String CAKE = "Conjured Mana Cake";
+    private final int BACKSTAGE_QUALITY_INCREASE_10_DAYS = 2;
+    private final int BACKSTAGE_QUALITY_INCREASE_5_DAYS = 3;
+    private GildedRose app;
+
+    @BeforeEach
+    void setup() {
+        this.app = new GildedRose(new Item[]{});
+    }
 
     @Test
     void foo() {
-        Item[] items = new Item[] { new Item("foo", 0, 0) };
+        Item[] items = new Item[]{new Item("foo", 0, 0)};
-        GildedRose app = new GildedRose(items);
+        this.app.items = items;
-        app.updateQuality();
+        this.app.updateQuality();
-        assertEquals("fixme", app.items[0].name);
+        assertEquals("foo", app.items[0].name);
     }
 
+    @Test
+    void testNoNegativeQuality() {
+        Item[] items = new Item[]{
+            new Item(AGED_BRIE, 0, 0),
+            new Item(BACKSTAGE, 0, 0),
+            new Item(SULFURAS, 0, 0),
+            new Item(CAKE, 0, 0)
+        };
+        this.app.items = items;
+        // update quality two times
+        this.app.updateQuality();
+        this.app.updateQuality();
+
+        // assert the quality is not negative
+        for (Item item :
+            this.app.items) {
+            assertTrue(item.quality >= 0);
+        }
+    }
+
+    @Test
+    void testAgedBrieQualityIncrease() {
+        Item[] items = new Item[]{new Item(AGED_BRIE, 0, 10)};
+        this.app.items = items;
+        // update quality two times
+        this.app.updateQuality();
+        this.app.updateQuality();
+        assertTrue(this.app.items[0].quality > 10);
+    }
+
+
+    @Test
+    void testQualityNeverMoreThan50() {
+        Item[] items = new Item[]{new Item(AGED_BRIE, 0, 50)};
+        this.app.items = items;
+        // update quality two times
+        this.app.updateQuality();
+        this.app.updateQuality();
+        assertTrue(this.app.items[0].quality <= 50);
+    }
+
+
+    @Test
+    void testSulfurasQualityNeverChange() {
+        Item[] items = new Item[]{new Item(SULFURAS, 2, 10)};
+        this.app.items = items;
+        // update quality two times
+        this.app.updateQuality();
+        this.app.updateQuality();
+        this.app.updateQuality();
+        assertEquals(10,this.app.items[0].quality);
+        assertEquals(2,this.app.items[0].sellIn );
+    }
+
+
+    @Test
+    void testBackstagePassQuality10DaysBeforeSellIn() {
+        Item[] items = new Item[]{new Item(BACKSTAGE, 9, 10)};
+        this.app.items = items;
+        // update quality two times
+        int noOfDays = 3;
+        for (int day = 0; day < noOfDays; day++) {
+            this.app.updateQuality();
+        }
+        int expectedQuality = 10 + BACKSTAGE_QUALITY_INCREASE_10_DAYS * noOfDays;
+        assertEquals(expectedQuality, this.app.items[0].quality);
+    }
+
+    @Test
+    void testBackstagePassQuality5DaysBeforeSellIn() {
+        Item[] items = new Item[]{new Item(BACKSTAGE, 5, 10)};
+        this.app.items = items;
+        // update quality two times
+        int noOfDays = 3;
+        for (int day = 0; day < noOfDays; day++) {
+            this.app.updateQuality();
+        }
+        int expectedQuality = 10 + BACKSTAGE_QUALITY_INCREASE_5_DAYS * noOfDays;
+        assertEquals(expectedQuality, this.app.items[0].quality);
+    }
+
+    @Test
+    void testBackstagePassQuality6DaysBeforeSellIn() {
+        Item[] items = new Item[]{new Item(BACKSTAGE, 6, 10)};
+        this.app.items = items;
+        // update quality two times
+        this.app.updateQuality();
+        int expectedQuality = 12;
+        assertEquals(expectedQuality, this.app.items[0].quality);
+    }
+
+    @Test
+    void testBackstagePassQuality11DaysBeforeSellIn() {
+        Item[] items = new Item[]{new Item(BACKSTAGE, 11, 10)};
+        this.app.items = items;
+        // update quality two times
+        this.app.updateQuality();
+        int expectedQuality = 11;
+        assertEquals(expectedQuality, this.app.items[0].quality);
+    }
+
+    @Test
+    void testBackstagePassQualityAfterSellIn() {
+        Item[] items = new Item[]{new Item(BACKSTAGE, 1, 10)};
+        this.app.items = items;
+        // update quality two times
+        int noOfDays = 2;
+        for (int day = 0; day < noOfDays; day++) {
+            this.app.updateQuality();
+        }
+        int expectedQuality = 0;
+        assertEquals(expectedQuality, this.app.items[0].quality);
+    }
+
+    @Test
+    void testNormalItemQualityDegradeTwiceAsFast() {
+        Item[] items = new Item[]{new Item(CAKE, 0, 10)};
+        this.app.items = items;
+        // update quality two times
+        int noOfDays = 2;
+        for (int day = 0; day < noOfDays; day++) {
+            this.app.updateQuality();
+        }
+        int expectedQuality = 6;
+        assertEquals(expectedQuality, this.app.items[0].quality);
+    }
+
+
 }

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

@@ -18,7 +18,7 @@ public class TexttestFixture {
 
         GildedRose app = new GildedRose(items);
 
-        int days = 2;
+        int days = 30;
         if (args.length > 0) {
             days = Integer.parseInt(args[0]) + 1;
         }