The Quality of an item is never negative

Java/pom.xml

@@ -28,6 +28,12 @@
             <version>${junit.jupiter.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-params</artifactId>
+            <version>${junit.jupiter.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>

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

@@ -1,6 +1,8 @@
 package com.gildedrose;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
 
 import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
 
@@ -10,17 +12,40 @@ class GildedRoseTest {
     @Test
     void shouldProcessFooItem() {
         // given
-        final Item[] items = new Item[]{new Item("foo", 0, 0)};
+        GildedRose app = prepareApp(new Item("foo", 0, 0));
-        GildedRose app = new GildedRose(items);
 
         // when
         app.updateQuality();
 
         // then
         final Item item = app.items[0];
-        assertThat(item.name).isEqualTo("foo");
+        assertItem(item, "foo", 0, -1);
-        assertThat(item.quality).isEqualTo(0);
-        assertThat(item.sellIn).isEqualTo(-1);
     }
 
+    @ParameterizedTest(name="Initial quality: {arguments}")
+    @ValueSource(ints={0,1})
+    void shouldTheQualityNeverBeNegative(int initialQuality) {
+        // given
+        GildedRose app = prepareApp(new Item("foo", 0, initialQuality));
+
+        // when
+        app.updateQuality();
+
+        // then
+        final Item item = app.items[0];
+        assertItem(item, "foo", 0, -1);
+    }
+
+    private void assertItem(Item item, String expectedName, int expectedQuality, int expectedSellIn) {
+        assertThat(item).as("item").isNotNull();
+        assertThat(item.name).as("name").isEqualTo(expectedName);
+        assertThat(item.quality).as("quality").isEqualTo(expectedQuality);
+        assertThat(item.sellIn).as("sellIn").isEqualTo(expectedSellIn);
+    }
+
+    private static GildedRose prepareApp(Item... items) {
+        return new GildedRose(items);
+    }
+
+
 }