Solution Java v1

Java/build.gradle

@@ -15,7 +15,7 @@ dependencies {
 
 group = 'com.gildedrose'
 version = '0.0.1-SNAPSHOT'
-sourceCompatibility = '1.8'
+sourceCompatibility = '14'
 
 test {
     useJUnitPlatform()

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

@@ -1,5 +1,9 @@
 package com.gildedrose;
 
+import com.gildedrose.policies.ItemUpdater;
+
+import java.util.Arrays;
+
 class GildedRose {
     Item[] items;
 
@@ -8,55 +12,6 @@ class GildedRose {
     }
 
     public void updateQuality() {
-        for (int i = 0; i < items.length; i++) {
+        Arrays.stream(items).forEach(ItemUpdater::updateItem);
-            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")) {
-                        if (items[i].sellIn < 11) {
-                            if (items[i].quality < 50) {
-                                items[i].quality = items[i].quality + 1;
-                            }
-                        }
-
-                        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")) {
-                items[i].sellIn = items[i].sellIn - 1;
-            }
-
-            if (items[i].sellIn < 0) {
-                if (!items[i].name.equals("Aged Brie")) {
-                    if (!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 {
-                        items[i].quality = items[i].quality - items[i].quality;
-                    }
-                } else {
-                    if (items[i].quality < 50) {
-                        items[i].quality = items[i].quality + 1;
-                    }
-                }
-            }
-        }
     }
-}
+}

Java/src/main/java/com/gildedrose/policies/AgedBrieUpdatePolicy.java

@@ -0,0 +1,15 @@
+package com.gildedrose.policies;
+
+import com.gildedrose.Item;
+
+class AgedBrieUpdatePolicy extends UpdatePolicy {
+    AgedBrieUpdatePolicy(Item item) {
+        super(item);
+    }
+
+    @Override
+    void updateItem() {
+        decreaseSellIn();
+        increaseQuality();
+    }
+}

Java/src/main/java/com/gildedrose/policies/BackstagePassesUpdatePolicy.java

@@ -0,0 +1,31 @@
+package com.gildedrose.policies;
+
+import com.gildedrose.Item;
+
+class BackstagePassesUpdatePolicy extends UpdatePolicy {
+    BackstagePassesUpdatePolicy(Item item) {
+        super(item);
+    }
+
+    @Override
+    void updateItem() {
+        decreaseSellIn();
+
+        var sellIn = item.sellIn;
+
+        if (sellIn < 0) {
+            item.quality = 0;
+            return;
+        }
+
+        increaseQuality();
+
+        if (sellIn < 10) {
+            increaseQuality();
+        }
+
+        if (sellIn < 5) {
+            increaseQuality();
+        }
+    }
+}

Java/src/main/java/com/gildedrose/policies/ConjuredUpdatePolicy.java

@@ -0,0 +1,15 @@
+package com.gildedrose.policies;
+
+import com.gildedrose.Item;
+
+class ConjuredUpdatePolicy extends UpdatePolicy {
+    ConjuredUpdatePolicy(Item item) {
+        super(item);
+    }
+
+    @Override
+    void updateItem() {
+        super.updateItem();
+        decreaseQuality();
+    }
+}

Java/src/main/java/com/gildedrose/policies/ItemUpdater.java

@@ -0,0 +1,10 @@
+package com.gildedrose.policies;
+
+import com.gildedrose.Item;
+
+public class ItemUpdater {
+
+    public static void updateItem(Item item){
+        UpdatePolicesFactory.getUpdatePolicy(item).updateItem();
+    }
+}

Java/src/main/java/com/gildedrose/policies/SulfurasUpdatePolicy.java

@@ -0,0 +1,14 @@
+package com.gildedrose.policies;
+
+import com.gildedrose.Item;
+
+class SulfurasUpdatePolicy extends UpdatePolicy{
+    SulfurasUpdatePolicy(Item item) {
+        super(item);
+    }
+
+    @Override
+    void updateItem() {
+        // Do nothing
+    }
+}

Java/src/main/java/com/gildedrose/policies/UpdatePolicesFactory.java

@@ -0,0 +1,17 @@
+package com.gildedrose.policies;
+
+import com.gildedrose.Item;
+
+ class UpdatePolicesFactory {
+
+     static UpdatePolicy getUpdatePolicy(Item item) {
+        return switch (item.name) {
+            case "Aged Brie" -> new AgedBrieUpdatePolicy(item);
+            case "Backstage passes to a TAFKAL80ETC concert" -> new BackstagePassesUpdatePolicy(item);
+            case "Sulfuras, Hand of Ragnaros" -> new SulfurasUpdatePolicy(item);
+            case "Conjured" -> new ConjuredUpdatePolicy(item);
+            default -> new UpdatePolicy(item);
+        };
+    }
+
+}

Java/src/main/java/com/gildedrose/policies/UpdatePolicy.java

@@ -0,0 +1,36 @@
+package com.gildedrose.policies;
+
+import com.gildedrose.Item;
+
+class UpdatePolicy {
+
+    private final int MAX_QUALITY = 50;
+    private final int MIN_QUALITY = 0;
+
+    protected Item item;
+
+    UpdatePolicy(Item item) {
+        this.item = item;
+    }
+
+    void updateItem() {
+        decreaseSellIn();
+        decreaseQuality();
+    }
+
+    void decreaseSellIn() {
+        item.sellIn -= 1;
+    }
+
+    void decreaseQuality() {
+        item.quality = item.quality <= MIN_QUALITY ? MIN_QUALITY : isExpired() ? item.quality - 2 : item.quality - 1;
+    }
+
+    void increaseQuality() {
+        item.quality = item.quality >= MAX_QUALITY ? MAX_QUALITY : isExpired() ? item.quality + 2 : item.quality + 1;
+    }
+
+    private boolean isExpired() {
+        return item.sellIn < 0;
+    }
+}

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

@@ -0,0 +1,56 @@
+package com.gildedrose;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class AgedBrieItemTest extends ItemTest {
+
+    @Override
+    @Test
+    void sellInDecreaseTest() {
+        Item[] items = new Item[] { new Item("Aged Brie", 2, 2) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+
+        assertEquals(3, app.items[0].quality);
+        assertEquals(1, app.items[0].sellIn);
+
+        app.updateQuality();
+
+        assertEquals(4, app.items[0].quality);
+        assertEquals(0, app.items[0].sellIn);
+    }
+
+    @Override
+    @Test
+    void afterSellInQualityChangeTest() {
+        Item[] items = new Item[] { new Item("Aged Brie", 1, 2) };
+        GildedRose app = new GildedRose(items);
+
+        app.updateQuality();
+
+        assertEquals(3, app.items[0].quality);
+        assertEquals(0, app.items[0].sellIn);
+
+        app.updateQuality();
+
+        assertEquals(5, app.items[0].quality);
+        assertEquals(-1, app.items[0].sellIn);
+    }
+
+    @Test
+    void qualityNotAbove50Test() {
+        Item[] items = new Item[] { new Item("Aged Brie", 2, 49) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+
+        assertEquals(50, app.items[0].quality);
+        assertEquals(1, app.items[0].sellIn);
+
+        app.updateQuality();
+
+        assertEquals(50, app.items[0].quality);
+        assertEquals(0, app.items[0].sellIn);
+    }
+}

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

@@ -0,0 +1,61 @@
+package com.gildedrose;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class BackstagePassesItemTest extends ItemTest{
+
+    @Override
+    @Test
+    void sellInDecreaseTest() {
+        Item[] items = new Item[] { new Item("Backstage passes to a TAFKAL80ETC concert", 11, 0),
+            new Item("Backstage passes to a TAFKAL80ETC concert", 6, 10) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+
+        assertEquals(1, app.items[0].quality);
+        assertEquals(10, app.items[0].sellIn);
+        assertEquals(12, app.items[1].quality);
+        assertEquals(5, app.items[1].sellIn);
+
+        app.updateQuality();
+
+        assertEquals(3, app.items[0].quality);
+        assertEquals(9, app.items[0].sellIn);
+        assertEquals(15, app.items[1].quality);
+        assertEquals(4, app.items[1].sellIn);
+    }
+
+    @Override
+    @Test
+    void afterSellInQualityChangeTest() {
+        Item[] items = new Item[] { new Item("Backstage passes to a TAFKAL80ETC concert", 1, 20) };
+        GildedRose app = new GildedRose(items);
+
+        app.updateQuality();
+
+        assertEquals(23, app.items[0].quality);
+        assertEquals(0, app.items[0].sellIn);
+
+        app.updateQuality();
+
+        assertEquals(0, app.items[0].quality);
+        assertEquals(-1, app.items[0].sellIn);
+    }
+
+    @Test
+    void qualityNotAbove50Test() {
+        Item[] items = new Item[] { new Item("Backstage passes to a TAFKAL80ETC concert", 2, 49) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+
+        assertEquals(50, app.items[0].quality);
+        assertEquals(1, app.items[0].sellIn);
+
+        app.updateQuality();
+
+        assertEquals(50, app.items[0].quality);
+        assertEquals(0, app.items[0].sellIn);
+    }
+}

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

@@ -0,0 +1,41 @@
+package com.gildedrose;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ConjuredItemTest extends ItemTest{
+
+    @Override
+    @Test
+    void sellInDecreaseTest() {
+        Item[] items = new Item[] { new Item("Conjured", 2, 10) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+
+        assertEquals(8, app.items[0].quality);
+        assertEquals(1, app.items[0].sellIn);
+
+        app.updateQuality();
+
+        assertEquals(6, app.items[0].quality);
+        assertEquals(0, app.items[0].sellIn);
+    }
+
+    @Override
+    @Test
+    void afterSellInQualityChangeTest() {
+        Item[] items = new Item[] { new Item("Conjured", 1, 20) };
+        GildedRose app = new GildedRose(items);
+
+        app.updateQuality();
+
+        assertEquals(18, app.items[0].quality);
+        assertEquals(0, app.items[0].sellIn);
+
+        app.updateQuality();
+
+        assertEquals(14, app.items[0].quality);
+        assertEquals(-1, app.items[0].sellIn);
+    }
+}

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

@@ -1,17 +0,0 @@
-package com.gildedrose;
-
-import org.junit.jupiter.api.Test;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
-class GildedRoseTest {
-
-    @Test
-    void foo() {
-        Item[] items = new Item[] { new Item("foo", 0, 0) };
-        GildedRose app = new GildedRose(items);
-        app.updateQuality();
-        assertEquals("fixme", app.items[0].name);
-    }
-
-}

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

@@ -0,0 +1,50 @@
+package com.gildedrose;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ItemTest {
+
+    @Test
+    void sellInDecreaseTest() {
+        Item[] items = new Item[] { new Item("foo", 2, 2) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+
+        assertEquals(1, app.items[0].quality);
+        assertEquals(1, app.items[0].sellIn);
+
+        app.updateQuality();
+
+        assertEquals(0, app.items[0].quality);
+        assertEquals(0, app.items[0].sellIn);
+    }
+
+    @Test
+    void notNegativeQualityTest() {
+        Item[] items = new Item[] { new Item("foo", 0, 0) };
+        GildedRose app = new GildedRose(items);
+
+        app.updateQuality();
+
+        assertEquals(0, app.items[0].quality);
+        assertEquals(-1, app.items[0].sellIn);
+    }
+
+    @Test
+    void afterSellInQualityChangeTest() {
+        Item[] items = new Item[] { new Item("foo", 1, 20) };
+        GildedRose app = new GildedRose(items);
+
+        app.updateQuality();
+
+        assertEquals(19, app.items[0].quality);
+        assertEquals(0, app.items[0].sellIn);
+
+        app.updateQuality();
+
+        assertEquals(17, app.items[0].quality);
+        assertEquals(-1, app.items[0].sellIn);
+    }
+}

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

@@ -0,0 +1,19 @@
+package com.gildedrose;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class SulfurasItemTest {
+
+    @Test
+    void standardChangeTest() {
+        Item[] items = new Item[] { new Item("Sulfuras, Hand of Ragnaros", 5, 80) };
+        GildedRose app = new GildedRose(items);
+
+        app.updateQuality();
+
+        assertEquals(80, app.items[0].quality);
+        assertEquals(5, app.items[0].sellIn);
+    }
+}