clean up test

InventoryTest.java

 import static org.junit.Assert.*;
 import java.util.Arrays;
 import org.junit.Test;
+import org.junit.Before;
 
 public class InventoryTest {
-	
-	@Test
-	public void should_never_changes_quailty_of_Sulfuras() throws Exception {
-		Item sulfuras = new Item("Sulfuras, Hand of Ragnaros", 0, 80);
-		
-		Inventory sut = new Inventory((Item[]) Arrays.asList(new Item("Sulfuras, Hand of Ragnaros", 0, 80)).toArray());
-		
-		sut.updateQuality();
-		
-		assertEquals(80, sulfuras.getQuality());
-		
-		
-	}
-	@Test
-	public void should_never_changes_sellIn_of_Sulfuras() throws Exception {
-		Item sulfuras = new Item("Sulfuras, Hand of Ragnaros", 0, 80);
-		
-		Inventory sut = new Inventory((Item[]) Arrays.asList(sulfuras).toArray());
-		
-		sut.updateQuality();
-		
-		assertEquals(0, sulfuras.getSellIn());
-		
-		
-	}
-	
-	
-	
-	@Test
-	public void should_lower_the_sellIn_by_one_for_normal_items() throws Exception {
-		Item normalItem = new Item("+5 Dexterity Vest", 10, 20);
-		
-		Inventory sut = new Inventory((Item[]) Arrays.asList(normalItem).toArray());
-		
-		sut.updateQuality();
-		
-		
-		assertEquals(9, normalItem.getSellIn());
-	}
-	
-	@Test
-	public void should_lower_the_quality_by_one_for_normal_items() throws Exception {
-		Item normalItem = new Item("+5 Dexterity Vest", 10, 20);
-		
-		Inventory sut = new Inventory((Item[]) Arrays.asList(normalItem).toArray());
-		
-		sut.updateQuality();
-		
-		
-		assertEquals(19, normalItem.getQuality());
-	}
-	
-	@Test
-	public void should_not_lower_the_quality_below_zero() throws Exception {
-		Item normalItem = new Item("+5 Dexterity Vest", 10, 0);
-		
-		Inventory sut = new Inventory((Item[]) Arrays.asList(normalItem).toArray());
-		
-		sut.updateQuality();
-		
-		
-		assertEquals(0, normalItem.getQuality());
-	}
-	
-	@Test
-	public void should_lower_the_quality_twice_as_fast_once_the_sell_in_date_has_passed() throws Exception {
-		Item normalItem = new Item("+5 Dexterity Vest", -1, 25);
-		
-		Inventory sut = new Inventory((Item[]) Arrays.asList(normalItem).toArray());
-		
-		sut.updateQuality();
-		
-		
-		assertEquals(23, normalItem.getQuality());
-	}
-	
-	
-	@Test
-	public void should_increase_the_quality_of_aged_brie_as_it_gets_older() throws Exception {
-		Item agedBrie = new Item("Aged Brie", 10, 25);
-		
-		Inventory sut = new Inventory((Item[]) Arrays.asList(agedBrie).toArray());
-		
-		sut.updateQuality();
-		
-		
-		assertEquals(26, agedBrie.getQuality());
-	}
-	
-	
-	@Test
-	public void should_not_increase_the_quality_of_aged_brie_over_50() throws Exception {
-		Item agedBrie = new Item("Aged Brie", 10, 50);
-		
-		Inventory sut = new Inventory((Item[]) Arrays.asList(agedBrie).toArray());
-		
-		sut.updateQuality();
-		
-		
-		assertEquals(50, agedBrie.getQuality());
-	}
-	
-	@Test
-	public void should_lower_backstage_passes_to_zero_quality_once_concert_has_happened() throws Exception {
-		Item backStagePass = new Item("Backstage passes to a TAFKAL80ETC concert", -1, 20);
-		
-		Inventory sut = new Inventory((Item[]) Arrays.asList(backStagePass).toArray());
-		
-		sut.updateQuality();
-		
-		
-		assertEquals(0, backStagePass.getQuality());
-	}
-	
-	@Test
-	public void should_increase_backstage_passes_quality_by_1_when_the_concert_is_more_than_10_days_away() throws Exception {
-		Item backStagePass = new Item("Backstage passes to a TAFKAL80ETC concert", 11, 20);
-		
-		Inventory sut = new Inventory((Item[]) Arrays.asList(backStagePass).toArray());
-		
-		sut.updateQuality();
-		
-		
-		assertEquals(21, backStagePass.getQuality());
-	}
-	
-	@Test
-	public void should_increase_backstage_passes_quality_by_2_when_the_concert_is_10_days_or_less_away() throws Exception {
-		Item backStagePass = new Item("Backstage passes to a TAFKAL80ETC concert", 10, 27);
-		
-		Inventory sut = new Inventory((Item[]) Arrays.asList(backStagePass).toArray());
-		
-		sut.updateQuality();
-		
-		
-		assertEquals(29, backStagePass.getQuality());
-	}
-	
-	@Test
-	public void should_increase_backstage_passes_quality_by_3_when_the_concert_is_5_days_or_less_away() throws Exception {
-		Item backStagePass = new Item("Backstage passes to a TAFKAL80ETC concert", 5, 44);
-		
-		Inventory sut = new Inventory((Item[]) Arrays.asList(backStagePass).toArray());
-		
-		sut.updateQuality();
-		
-		
-		assertEquals(47, backStagePass.getQuality());
-	}
-	
-	@Test
-	public void should_not_increase_backstage_passes_above_a_quality_of_50() throws Exception {
-		Item backStagePassMoreThan10DaysAway = new Item("Backstage passes to a TAFKAL80ETC concert", 15, 50);
-		
-		Item backStagePass10DaysAway = new Item("Backstage passes to a TAFKAL80ETC concert", 5, 49);
-		Item backStagePass5DaysAway = new Item("Backstage passes to a TAFKAL80ETC concert", 5, 48);
-		
-		Inventory sut = new Inventory((Item[]) Arrays.asList(backStagePassMoreThan10DaysAway, backStagePass10DaysAway, backStagePass5DaysAway).toArray());
-		
-		sut.updateQuality();
-		
-		
-		assertEquals(50, backStagePassMoreThan10DaysAway.getQuality());
-		assertEquals(50, backStagePass10DaysAway.getQuality());
-		assertEquals(50, backStagePass5DaysAway.getQuality());
-	}
-	
-	
-	
-	
-	
-	
-	
+    private static final int MAX_QUALITY = 50;
+    private static final String AGED_BRIE_NAME = "Aged Brie";
+    private static final String BACKSTAGE_PASS_NAME = "Backstage passes to a TAFKAL80ETC concert";
+    private static final String NORMAL_ITEM_NAME = "+5 Dexterity Vest";
+
+    private Item sulfuras;
+    private Item normalItem;
+
+    @Before
+    public void setup(){
+        sulfuras = new Item("Sulfuras, Hand of Ragnaros", 0, 80);
+        normalItem = new Item(NORMAL_ITEM_NAME, 10, 20);
+    }
+
+    @Test
+    public void testUpdate_ForSulfurasQuality() throws Exception {
+        int expectedQuality = sulfuras.getQuality();
+        Item[] items = {sulfuras};
+        Inventory sut = new Inventory(items);
+
+        sut.updateQuality();
+
+        assertEquals(expectedQuality, sulfuras.getQuality());
+    }
+    @Test
+    public void testUpdate_ForSulfurasSellIn() throws Exception {
+        int expectedSellIn = sulfuras.getSellIn();
+        Item[] items = {sulfuras};
+        Inventory sut = new Inventory(items);
+
+        sut.updateQuality();
+
+        assertEquals(expectedSellIn, sulfuras.getSellIn());
+    }
+
+    @Test
+    public void testUpdate_ForNormalItemSellIn() throws Exception {
+        int expectedSellIn = normalItem.getSellIn() - 1;
+        Item[] items = {normalItem};
+        Inventory sut = new Inventory(items);
+
+        sut.updateQuality();
+
+        assertEquals(expectedSellIn, normalItem.getSellIn());
+    }
+
+    @Test
+    public void testUpdate_ForNormalItemQuantity() throws Exception {
+        int expectedQuality = normalItem.getQuality() - 1;
+        Item[] items = {normalItem};
+        Inventory sut = new Inventory(items);
+
+        sut.updateQuality();
+
+        assertEquals(expectedQuality, normalItem.getQuality());
+    }
+
+    @Test
+    public void testUpdate_ForSoldOutItem() throws Exception {
+        int minimumQuality = 0;
+        Item normalItemWithMinimumQuality = new Item(NORMAL_ITEM_NAME, 10, minimumQuality);
+        Item[] items = {normalItemWithMinimumQuality};
+        Inventory sut = new Inventory(items);
+
+        sut.updateQuality();
+
+        assertEquals(minimumQuality, normalItemWithMinimumQuality.getQuality());
+    }
+
+    @Test
+    public void testUpdate_ForNormalItemOnceTheSellInDatePassed() throws Exception {
+        Item normalItemWithPassedSellDate = new Item(NORMAL_ITEM_NAME, -1, 25);
+        int expectedQuality = normalItemWithPassedSellDate.getQuality() - 2;
+        Item[] items = {normalItemWithPassedSellDate};
+        Inventory sut = new Inventory(items);
+
+        sut.updateQuality();
+
+        assertEquals(expectedQuality, normalItemWithPassedSellDate.getQuality());
+    }
+
+    @Test
+    public void testUpdate_AgedBrie() throws Exception {
+        Item agedBrie = new Item(AGED_BRIE_NAME, 10, 25);
+        int expectedQuality = agedBrie.getQuality() + 1;
+        Item[] items = {agedBrie};
+        Inventory sut = new Inventory(items);
+
+        sut.updateQuality();
+
+        assertEquals(expectedQuality, agedBrie.getQuality());
+    }
+
+    @Test
+    public void testUpdate_WhenAgedBrieIsAtMaxQuality() throws Exception {
+        Item agedBrie = new Item(AGED_BRIE_NAME, 10, MAX_QUALITY);
+        Item[] items = {agedBrie};
+        Inventory sut = new Inventory(items);
+
+        sut.updateQuality();
+
+        assertEquals(MAX_QUALITY, agedBrie.getQuality());
+    }
+
+    @Test
+    public void testUpdate_ForBackstagePassesAfterTheConcertOccurred() throws Exception {
+        Item backStagePass = new Item(BACKSTAGE_PASS_NAME, -1, 20);
+        Item[] items = {backStagePass};
+        Inventory sut = new Inventory(items);
+
+        sut.updateQuality();
+
+        assertEquals(0, backStagePass.getQuality());
+    }
+
+    @Test
+    public void testUpdate_ForBackstagePassesQualityWhenTheConcertIsMoreThan10DaysAway() throws Exception {
+        Item backStagePass = new Item(BACKSTAGE_PASS_NAME, 11, 20);
+        int expectedQuality = backStagePass.getQuality() + 1;
+        Item[] items = {backStagePass};
+        Inventory sut = new Inventory(items);
+
+        sut.updateQuality();
+
+        assertEquals(21, backStagePass.getQuality());
+    }
+
+    @Test
+    public void testUpdate_ForBackstagePassesWhenTheConcertIs10DaysOrLessAway() throws Exception {
+        Item backStagePass = new Item(BACKSTAGE_PASS_NAME, 10, 27);
+        int expectedQuality = backStagePass.getQuality() + 2;
+        Item[] items = {backStagePass};
+        Inventory sut = new Inventory(items);
+
+        sut.updateQuality();
+
+        assertEquals(expectedQuality, backStagePass.getQuality());
+    }
+
+    @Test
+    public void testUpdate_ForBackstagePassesWhenTheConcertIs5DaysOrLessAway() throws Exception {
+        Item backStagePass = new Item(BACKSTAGE_PASS_NAME, 5, 44);
+        int expectedQuality = backStagePass.getQuality() + 3;
+        Item[] items = {backStagePass};
+        Inventory sut = new Inventory(items);
+
+        sut.updateQuality();
+
+        assertEquals(expectedQuality, backStagePass.getQuality());
+    }
+
+    @Test
+    public void testUpdate_WhenBackstagePassesIsAtOrNeaerMaxQuality() throws Exception {
+        Item backStagePassMoreThan10DaysAway = new Item(BACKSTAGE_PASS_NAME, 15, MAX_QUALITY);
+        Item backStagePass10DaysAway = new Item(BACKSTAGE_PASS_NAME, 10, MAX_QUALITY - 1);
+        Item backStagePass5DaysAway = new Item(BACKSTAGE_PASS_NAME, 5, MAX_QUALITY - 2);
+
+        Item[] items = {backStagePassMoreThan10DaysAway, backStagePass10DaysAway, backStagePass5DaysAway};
+        Inventory sut = new Inventory(items);
+
+        sut.updateQuality();
+
+        assertEquals(MAX_QUALITY, backStagePassMoreThan10DaysAway.getQuality());
+        assertEquals(MAX_QUALITY, backStagePass10DaysAway.getQuality());
+        assertEquals(MAX_QUALITY, backStagePass5DaysAway.getQuality());
+    }
 }