The Quality of an item is never negative

Java/README.md

@@ -11,7 +11,7 @@
 # unit tests
 -[x] At the end of each day our system lowers both values for every item
 -[x] Once the sell by date has passed, Quality degrades twice as fast
--[ ] The Quality of an item is never negative
+-[x] The Quality of an item is never negative
 -[ ] "Aged Brie" actually increases in Quality the older it gets
 -[ ] The Quality of an item is never more than 50
 -[ ] "Sulfuras", being a legendary item, never has to be sold or decreases in Quality

Java/pom.xml

@@ -11,13 +11,15 @@
 
     <properties>
         <java.version>1.8</java.version>
+        <junit-jupiter.version>5.5.2</junit-jupiter.version>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>
 
     <dependencies>
         <dependency>
-            <groupId>junit</groupId>
+            <groupId>org.junit.jupiter</groupId>
-            <artifactId>junit</artifactId>
+            <artifactId>junit-jupiter-engine</artifactId>
-            <version>4.12</version>
+            <version>${junit-jupiter.version}</version>
             <scope>test</scope>
         </dependency>
     </dependencies>
@@ -31,6 +33,15 @@
                     <target>${java.version}</target>
                 </configuration>
             </plugin>
+
+
+            <!-- Need at least 2.22.0 to support JUnit 5 -->
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>3.0.0-M3</version>
+            </plugin>
+
         </plugins>
     </build>
 

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

@@ -1,8 +1,9 @@
 package com.gildedrose;
 
-import static org.junit.Assert.*;
+import static org.junit.jupiter.api.Assertions.*;
 
-import org.junit.Test;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
 
 public class GildedRoseTest {
 
@@ -14,8 +15,8 @@ public class GildedRoseTest {
         assertEquals("foo", app.items[0].name);
     }
 
-    //At the end of each day our system lowers both values for every item
     @Test
+    @DisplayName("At the end of each day our system lowers both values for every item")
     public void shouldLowerBothValues(){
         Item[] items = new Item[] { TestHelper.getItem("foobar", 2, 2) };
         GildedRose app = new GildedRose(items);
@@ -24,8 +25,8 @@ public class GildedRoseTest {
         assertEquals(1, app.items[0].sellIn);
     }
 
-    //Once the sell by date has passed (<=0), Quality degrades twice as fast
     @Test
+    @DisplayName("Once the sell by date has passed (<=0), Quality degrades twice as fast")
     public void shouldDowngradeTwiceAsFastAfterSellDate(){
         Item[] items = new Item[] { TestHelper.getItem("foobar", 1, 5) };
         GildedRose app = new GildedRose(items);
@@ -41,4 +42,19 @@ public class GildedRoseTest {
         assertEquals(-1, app.items[0].sellIn);
     }
 
+    @Test
+    @DisplayName("The Quality of an item is never negative")
+    public void shouldNeverHaveANegativeQuality() {
+        Item[] items = new Item[]{TestHelper.getItem("foobar", 0, 0)};
+        GildedRose app = new GildedRose(items);
+
+        //day 1, drop by 1
+        app.updateQuality();
+        assertEquals(0, app.items[0].quality);
+
+        //day 2, drop by 1 => quality is still 0
+        app.updateQuality();
+        assertEquals(0, app.items[0].quality);
+    }
+
 }