From 7e3e5d0d7c2421653a0c0bcae4c372fd3028c93f Mon Sep 17 00:00:00 2001
From: Bjorn Misseghers <bjorn.misseghers@unifiedpost.com>
Date: Tue, 13 Apr 2021 10:03:27 +0200
Subject: [PATCH] Implement faster quality decrease after sellIn

Quality decreases by 2 after the sellIn reaches 0
---
 .../quality/DefaultQualityBehavior.java       |  7 +++-
 .../quality/DefaultQualityBehaviorTest.java   | 34 ++++++++++++++++---
 2 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/Java/src/main/java/com/gildedrose/behavior/quality/DefaultQualityBehavior.java b/Java/src/main/java/com/gildedrose/behavior/quality/DefaultQualityBehavior.java
index ffa72474..3e86f16f 100644
--- a/Java/src/main/java/com/gildedrose/behavior/quality/DefaultQualityBehavior.java
+++ b/Java/src/main/java/com/gildedrose/behavior/quality/DefaultQualityBehavior.java
@@ -6,6 +6,8 @@ public class DefaultQualityBehavior implements QualityBehavior {
 
     public static final int MAX_QUALITY_LEVEL = 50;
     public static final int MIN_QUALITY_LEVEL = 0;
+    public static final int DEFAULT_QUALITY_DECREASE = 1;
+    public static final int FASTER_QUALITY_DECREASE = 2;
 
     @Override
     public void processQualityUpdate(Item item) {
@@ -13,9 +15,12 @@ public class DefaultQualityBehavior implements QualityBehavior {
     }
 
     private void decreaseQuality(Item item) {
-        item.quality = limitQuality(item.quality - 1);
+        item.quality = limitQuality(item.quality - getQualityDecreaseAmount(item));
     }
 
+    private int getQualityDecreaseAmount(Item item) {
+        return item.sellIn > 0 ? DEFAULT_QUALITY_DECREASE : FASTER_QUALITY_DECREASE;
+    }
     private int limitQuality(int newQuality) {
         return Math.max(MIN_QUALITY_LEVEL, Math.min(MAX_QUALITY_LEVEL, newQuality));
     }
diff --git a/Java/src/test/java/com/gildedrose/behavior/quality/DefaultQualityBehaviorTest.java b/Java/src/test/java/com/gildedrose/behavior/quality/DefaultQualityBehaviorTest.java
index 7708c8c5..ce5b13fd 100644
--- a/Java/src/test/java/com/gildedrose/behavior/quality/DefaultQualityBehaviorTest.java
+++ b/Java/src/test/java/com/gildedrose/behavior/quality/DefaultQualityBehaviorTest.java
@@ -17,7 +17,7 @@ public class DefaultQualityBehaviorTest {
 
     @Test
     void decreaseQuality() {
-        Item item = getItem(10);
+        Item item = getItem(5,10);
         qualityBehavior.processQualityUpdate(item);
 
         assertEquals(9, item.quality);
@@ -25,7 +25,7 @@ public class DefaultQualityBehaviorTest {
 
     @Test
     void decreaseNegativeQuality() {
-        Item item = getItem(-10);
+        Item item = getItem(5,-10);
         qualityBehavior.processQualityUpdate(item);
 
         assertEquals(0, item.quality);
@@ -33,13 +33,37 @@ public class DefaultQualityBehaviorTest {
 
     @Test
     void decreaseQualityZero() {
-        Item item = getItem(0);
+        Item item = getItem(5,0);
         qualityBehavior.processQualityUpdate(item);
 
         assertEquals(0, item.quality);
     }
 
-    private Item getItem(int quality) {
-        return new Item("SomeItem", 0, quality);
+    @Test
+    void decreaseQualityFaster() {
+        Item item = getItem(0,4);
+        qualityBehavior.processQualityUpdate(item);
+
+        assertEquals(2, item.quality);
+    }
+
+    @Test
+    void decreaseQualityFasterNegativeSellIn() {
+        Item item = getItem(-1,4);
+        qualityBehavior.processQualityUpdate(item);
+
+        assertEquals(2, item.quality);
+    }
+
+    @Test
+    void decreaseQualityFasterRespectLowerLimit() {
+        Item item = getItem(0,1);
+        qualityBehavior.processQualityUpdate(item);
+
+        assertEquals(0, item.quality);
+    }
+
+    private Item getItem(int sellIn, int quality) {
+        return new Item("SomeItem", sellIn, quality);
     }
 }