Add GildedRose-Refactoring-Kata refactoring

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

@@ -1,62 +1,22 @@
 package com.gildedrose;
 
+
+import com.gildedrose.updater.UpdaterFactory;
+import com.gildedrose.utils.EncapsulatedItem;
+
+import java.util.Objects;
+
+
 class GildedRose {
-    Item[] items;
+    final EncapsulatedItem[] items;
 
-    public GildedRose(Item[] items) {
-        this.items = items;
+    public GildedRose(final EncapsulatedItem[] items) {
+        Objects.requireNonNull(items, "Null EncapsulateItem[] items");
+        this.items = items.clone();
     }
-
     public void updateQuality() {
-        for (int i = 0; i < items.length; i++) {
-            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;
-                    }
-                }
-            }
+        for(final EncapsulatedItem item: items){
+            UpdaterFactory.getUpdater(item).update();
         }
     }
 }

src/main/java/com/gildedrose/product/category/AgedBrie.java

@@ -0,0 +1,38 @@
+package com.gildedrose.product.category;
+
+import com.gildedrose.Item;
+import com.gildedrose.updater.GenericUpdater;
+import com.gildedrose.utils.EncapsulatedItem;
+
+/**
+ * Aged Brie class handler.
+ * Conditions:
+ * <ul>
+ *     <li>"Aged Brie" actually increases in Quality the older it gets</li>
+ *     <li>Increases Expired Date</li>
+ * </ul>
+ *
+ */
+public class AgedBrie<T extends EncapsulatedItem> extends GenericUpdater<T> {
+
+
+    /**
+     * Constructor that creates a AgedBrie Object.
+     * @param item  the Age Brie {@link Item}
+     */
+    public AgedBrie(final T item) {
+        super(item);
+    }
+    /**
+     * "Aged Brie" actually increases in Quality the older it gets
+     */
+    protected void updateAfterSaleDate(final EncapsulatedItem item) {
+        increasesQuality(item);
+    }
+    /**
+     * {@inheritDoc}
+     */
+    protected void updateQuality(final EncapsulatedItem item) {
+        increasesQuality(item);
+    }
+}

src/main/java/com/gildedrose/product/category/BackStagePass.java

@@ -0,0 +1,51 @@
+package com.gildedrose.product.category;
+
+import com.gildedrose.updater.GenericUpdater;
+import com.gildedrose.utils.EncapsulatedItem;
+
+/**
+ * BackstagePass class handler ().
+ * Conditions:
+ * <ul>
+ *     <li>Quality increases by 2 when there are 10 days or less and by 3 when there are 5 days or less.</li>
+ *     <li>Quality drops to 0 after the concert</li>
+ * </ul>
+ *
+ */
+public class BackStagePass<T extends EncapsulatedItem> extends GenericUpdater<T> {
+
+    /**
+     * Represent 5 days
+     */
+    private static final int QUALITY_DAY_X2 = 5;
+    /**
+     * Represent 10 days
+     */
+    private static final int QUALITY_DAY_X3 = 10;
+
+    /**
+     * Constructor that creates a BackstagePass Object.
+     * @param item  the Back Stage Pass {@link EncapsulatedItem}
+     */
+    public BackStagePass(final T item) {
+        super(item);
+    }
+    /**
+     * <p>Quality drops to 0 after the concert.</p>
+     */
+    protected void updateAfterSaleDate(final EncapsulatedItem item) {
+        item.setQuality(0);
+    }
+    /**
+     * <p>Quality increases by 2 when there are 10 days or less and by 3 when there are 5 days or less.</p>
+     */
+    protected void updateQuality(final EncapsulatedItem item) {
+        increasesQuality(item);
+        if (item.getSellIn() <= QUALITY_DAY_X3) {
+            increasesQuality(item);
+        }
+        if (item.getSellIn() <= QUALITY_DAY_X2) {
+            increasesQuality(item);
+        }
+    }
+}

src/main/java/com/gildedrose/product/category/Conjured.java

@@ -0,0 +1,32 @@
+package com.gildedrose.product.category;
+
+import com.gildedrose.updater.GenericUpdater;
+import com.gildedrose.utils.EncapsulatedItem;
+
+/**
+ * Conjures class handler ().
+ * Conditions:
+ * <ul>
+ *     <li>"Conjured" items degrade in Quality twice as fast as normal items.</li>
+ * </ul>
+ *
+ */
+public class Conjured <T extends EncapsulatedItem> extends GenericUpdater<T> {
+
+    private static final int decrementFactor = 2;
+    private static final int incrementFactor = 2;
+
+    /**
+     * Constructor that creates a Conjured Object.
+     * @param item  the Conjured {@link EncapsulatedItem}
+     */
+    public Conjured(final T item) {
+        super(item, incrementFactor, decrementFactor);
+    }
+    /**
+     * {@inheritDoc}
+     */
+    protected void updateQuality(final EncapsulatedItem item) {
+        lowerQuality(item);
+    }
+}

src/main/java/com/gildedrose/product/category/Legendary.java

@@ -0,0 +1,42 @@
+package com.gildedrose.product.category;
+
+import com.gildedrose.updater.GenericUpdater;
+import com.gildedrose.utils.EncapsulatedItem;
+
+/**
+ * Legendary class handler ().
+ * Conditions:
+ * <ul>
+ *     <li>Never has to be sold or decreases in Quality.</li>
+ * </ul>
+ *
+ */
+public class Legendary <T extends EncapsulatedItem> extends GenericUpdater<T> {
+
+    //TODO: All the legendary item have immutable quality of 80 or just only the Sulfuras?
+    /**
+     * Constructor that creates a Legendary Object.
+     * @param item  the Legendary {@link EncapsulatedItem}
+     */
+    public Legendary(final T item) {
+        super(item);
+    }
+    /**
+     * {@inheritDoc}
+     */
+    protected void updateAfterSaleDate(final EncapsulatedItem item) {
+        // do nothing
+    }
+    /**
+     * {@inheritDoc}
+     */
+    protected void updateSellIn(final EncapsulatedItem item) {
+        // do nothing
+    }
+    /**
+     * {@inheritDoc}
+     */
+    protected void updateQuality(final EncapsulatedItem item) {
+        // do nothing
+    }
+}

src/main/java/com/gildedrose/updater/GenericUpdater.java

@@ -0,0 +1,124 @@
+package com.gildedrose.updater;
+
+import com.gildedrose.Item;
+import com.gildedrose.product.category.AgedBrie;
+import com.gildedrose.product.category.BackStagePass;
+import com.gildedrose.product.category.Conjured;
+import com.gildedrose.product.category.Legendary;
+import com.gildedrose.utils.EncapsulatedItem;
+
+/**
+ * Generic updater for products. All those products that do not require a custom
+ * update can / should use this class and the default methods.
+ */
+public class GenericUpdater<T extends EncapsulatedItem> implements Updater  {
+
+    /**
+     * <p>the value associated with the instance to decrement.</p>
+     */
+    private final int decrementQualityFactor;
+    /**
+     * <p>the value associated with the instance to increment.</p>
+     */
+    private final int incrementQualityFactor;
+    /**
+     * <p>The maximum size to which the quality can be.</p>
+     */
+    private static final int MAX_QUALITY = 50;
+
+    /**
+     * <p>The {@link EncapsulatedItem} to update.</p>
+     */
+    private final EncapsulatedItem item;
+
+    /**
+     * <p>Constructor for GenericUpdater.</p>
+     *
+     * @param item the {@link EncapsulatedItem} to manipulate
+     */
+    public GenericUpdater(final T item) {
+        this.item = item;
+        this.incrementQualityFactor = 1;
+        this.decrementQualityFactor = 1;
+    }
+
+    /**
+     * <p>Constructor for GenericUpdater.</p>
+     *
+     * @param item the {@link Item} to update
+     * @param incrementQualityFactor the value associated with the instance to increment
+     * @param decrementQualityFactor  the value associated with the instance to decrement
+     */
+    public GenericUpdater(final T item, final int incrementQualityFactor, final int decrementQualityFactor) {
+        this.item = item;
+        this.incrementQualityFactor = incrementQualityFactor;
+        this.decrementQualityFactor = decrementQualityFactor;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void update() {
+        updateQuality(item);
+        updateSellIn(item);
+        if (item.getSellIn() < 0) {
+            updateAfterSaleDate(item);
+        }
+    }
+
+    /**
+     * <p>Increment the quality of tge given {@link EncapsulatedItem}.</p>
+     *
+     * @param item the {@link EncapsulatedItem} to update the quality.
+     *
+     */
+        protected void increasesQuality(final EncapsulatedItem item) {
+        if (item.getQuality() < MAX_QUALITY) {
+            item.setQuality(item.getQuality() + incrementQualityFactor);
+        }
+    }
+    /**
+     * <p>Update the expired properties of tge given {@link EncapsulatedItem}.</p>
+     * <p>It depends on each product how to update the quality after the sale date</p>
+     *
+     * @see AgedBrie
+     * @see Legendary
+     * @see BackStagePass
+     * @see Conjured
+     *
+     * @param item the {@link EncapsulatedItem} to update the quality.
+     */
+    protected void updateAfterSaleDate(final EncapsulatedItem item) {
+        lowerQuality(item);
+    }
+    /**
+     * <p>Update the Quality properties of tge given {@link EncapsulatedItem}.</p>
+     *
+     * @param item the {@link EncapsulatedItem} to update the quality.
+     *
+     */
+    protected void updateQuality(final EncapsulatedItem item) {
+        lowerQuality(item);
+    }
+    /**
+     * <p>Decrement the quality of tge given {@link EncapsulatedItem}.</p>
+     *
+     * @param item the {@link EncapsulatedItem} to update the quality.
+     *
+     */
+    protected void lowerQuality(final EncapsulatedItem item) {
+        if (item.getQuality() > 0) {
+            item.setQuality(item.getQuality() - decrementQualityFactor);
+        }
+    }
+    /**
+     * <p>Update the sell in properties of tge given {@link EncapsulatedItem}.</p>
+     *
+     * @param item the {@link EncapsulatedItem} to update the quality.
+     *
+     */
+    protected void updateSellIn(final EncapsulatedItem item) {
+        item.setSellIn(item.getSellIn() - 1);
+    }
+}

src/main/java/com/gildedrose/updater/Updater.java

@@ -0,0 +1,15 @@
+package com.gildedrose.updater;
+
+import com.gildedrose.utils.EncapsulatedItem;
+
+/**
+ * Base interface from where all the different product updaters will implement.
+ * Contain only one abstract method {@code update}
+ */
+public interface Updater{
+
+    /**
+     * Updates the {@link EncapsulatedItem} properties
+     */
+    void update();
+}

src/main/java/com/gildedrose/updater/UpdaterFactory.java

@@ -0,0 +1,54 @@
+package com.gildedrose.updater;
+
+import com.gildedrose.product.category.Conjured;
+import com.gildedrose.utils.Articles;
+import com.gildedrose.product.category.AgedBrie;
+import com.gildedrose.product.category.BackStagePass;
+import com.gildedrose.product.category.Legendary;
+import com.gildedrose.utils.EncapsulatedItem;
+
+import java.util.Objects;
+
+/**
+ * <p>Factory class that is responsible for returning the right object type from a given item.</p>
+ */
+public class UpdaterFactory {
+
+    /**
+     * Main method of the factory. It receives an item and based on the name it
+     * generates an object according to the category.</p>
+     *
+     *  <p>If the name of the item can't found in the {@link Articles} will be return a default implementation
+     *  {@link GenericUpdater} </p>
+     *
+     * These can be:
+     * <ul>
+     *     <li>AgedBrie {@link AgedBrie}</li>
+     *     <li>BackStagePass {@link BackStagePass}</li>
+     *     <li>Conjured {@link Conjured}</li>
+     *      <li>Legendary {@link Legendary}</li>
+     * </ul>
+     * @see AgedBrie
+     * @see Legendary
+     * @see BackStagePass
+     * @see Conjured
+     * @see GenericUpdater
+     * @return  a new implementation of {@link Updater} given the input {@code item},
+     * @throws NullPointerException if {@code item} is {@code null}
+     */
+    public static Updater getUpdater(final EncapsulatedItem item) {
+        Objects.requireNonNull(item, "Null EncapsulateItem items");
+        switch (Articles.getArticle(item.getName())){
+            case AGED_BRIE:
+               return new AgedBrie<>(item);
+            case SULFURAS:
+                return new Legendary<>(item);
+            case TAFKAL_80ETC:
+                return new BackStagePass<>(item);
+            case CONJURED:
+                return new Conjured<>(item);
+            default:
+              return new GenericUpdater<>(item);
+        }
+    }
+}

src/main/java/com/gildedrose/utils/Articles.java

@@ -0,0 +1,77 @@
+package com.gildedrose.utils;
+
+
+/**
+ * The {@link Articles} enum defines types of a Articles.
+ * The following types are defined:
+ * <ul>
+ *     <li>Aged Brie</li>
+ *     <li>Backstage passes to a TAFKAL80ETC concert</li>
+ *     <li>Sulfuras, Hand of Ragnaros</li>
+ *     <li>Conjured Mana Cake</li>
+ *     <li>Default</li>
+ * </ul>
+ */
+public enum Articles {
+
+    /**
+     * Aged Brie
+     */
+    AGED_BRIE ("Aged Brie"),
+
+    /**
+     * the Backstage passes
+     */
+    TAFKAL_80ETC ("Backstage passes to a TAFKAL80ETC concert"),
+
+    /**
+     * Sulfuras, Hand of Ragnaros
+     */
+    SULFURAS ("Sulfuras, Hand of Ragnaros"),
+    /**
+     * Conjured Mana Cake
+     */
+    CONJURED ("Conjured Mana Cake"),
+
+    /**
+     * Unknown article.
+     */
+    DEFAULT ("DEFAULT");
+
+    /**
+     * The article name.
+     */
+    private final String article;
+
+    Articles(final String article) {
+        this.article = article;
+    }
+
+    /**
+     * Gets the article name.
+     *
+     * @return the article.
+     */
+    public String getArticle() {
+        return article;
+    }
+
+    /**
+     * Gets the article name given an article.
+     *
+     * @param article the article String to match
+     * @return the article given a {@code}. {@code DEFAULT} if not found, can be null
+     */
+    public static Articles getArticle(final String article) {
+        for (final Articles a : values()) {
+            if (a.getArticle().equals(article)) {
+                return a;
+            }
+        }
+        return DEFAULT;
+    }
+
+
+
+
+}

src/main/java/com/gildedrose/utils/EncapsulateItemBuilder.java

@@ -0,0 +1,58 @@
+package com.gildedrose.utils;
+
+/**
+ * <p>Builder for the object {@link EncapsulatedItem}.</p>
+ */
+public class EncapsulateItemBuilder {
+
+    /**
+     * The name of the product.
+     */
+    private String name;
+    /**
+     * SellIn value which denotes the number of days we have to sell the item.
+     */
+    private int sellIn;
+    /**
+     * Quality value which denotes how valuable the item is.
+     */
+    private int quality;
+
+    /**
+     * Constructs a new instance of Encapsulate ItemBuilder which initialize
+     * the {@code name}, {@code sellIn} and {@code quality}.
+     */
+    public EncapsulateItemBuilder() {
+        this.name = "";
+        this.quality = 0;
+        this.sellIn = 0;
+    }
+    /**
+     * <p>Set the name of the item.</p>
+     */
+    public EncapsulateItemBuilder named(final String name) {
+        this.name = name;
+        return this;
+    }
+    /**
+     * <p>Set the quality value.</p>
+     */
+    public EncapsulateItemBuilder ofQuality(final int quality) {
+        this.quality = quality;
+        return this;
+    }
+    /**
+     * <p>Set the sellIn value.</p>
+     */
+    public EncapsulateItemBuilder toSellIn(final int sellIn) {
+        this.sellIn = sellIn;
+        return this;
+    }
+
+    /**
+     * Create the {@link EncapsulatedItem} object from all the previously set data.
+     */
+    public EncapsulatedItem build() {
+        return new EncapsulatedItem(name, sellIn, quality);
+    }
+}

src/main/java/com/gildedrose/utils/EncapsulatedItem.java

@@ -0,0 +1,85 @@
+package com.gildedrose.utils;
+
+import java.io.Serializable;
+
+/**
+ * <p>Item copy object with all data encapsulated.</p>
+ */
+public class EncapsulatedItem implements Serializable {
+
+    private static final long serialVersionUID = 1989175797960240011L;
+    /**
+     * The name of the product.
+     */
+    private String name;
+    /**
+     * SellIn value which denotes the number of days we have to sell the item.
+     */
+    private int sellIn;
+    /**
+     * Quality value which denotes how valuable the item is.
+     */
+    private int quality;
+
+    /**
+     * Constructs a new instance of EncapsulateItem with the given {@code name}, {@code sellIn} and {@code quality}.
+     * @param name The name of the product.
+     * @param sellIn  The number of days we have to sell the item
+     * @param quality The value which denotes how valuable the item is
+     */
+    public EncapsulatedItem(final String name, final int sellIn, final int quality) {
+        this.setName(name);
+        this.setSellIn(sellIn);
+        this.setQuality(quality);
+    }
+
+    /**
+     * <p>Gets the name suitable for display.</p>
+     *
+     * @return the name.
+     */
+    public String getName() {
+        return name;
+    }
+
+    /**
+     * <p>Set the name of the item.</p>
+     */
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    /**
+     * <p>Gets the sell in suitable for display.</p>
+     *
+     * @return the sellIn value.
+     */
+    public int getSellIn() {
+        return sellIn;
+    }
+    /**
+     * <p>Set the sellIn value.</p>
+     */
+    public void setSellIn(final  int sellIn) {
+        this.sellIn = sellIn;
+    }
+    /**
+     * <p>Gets the quality suitable for display.</p>
+     *
+     * @return the quality value.
+     */
+    public int getQuality() {
+        return quality;
+    }
+    /**
+     * <p>Set the quality value.</p>
+     */
+    public void setQuality(final int quality) {
+        this.quality = quality;
+    }
+
+    @Override
+    public String toString() {
+        return this.getName() + ", " + this.getSellIn() + ", " + this.getQuality();
+    }
+}

src/test/java/com/gildedrose/AgedBrieTest.java

@@ -0,0 +1,96 @@
+package com.gildedrose;
+
+import com.gildedrose.utils.Articles;
+import com.gildedrose.utils.EncapsulatedItem;
+import org.junit.jupiter.api.Test;
+
+
+import static org.junit.jupiter.api.Assertions.assertAll;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+/**
+ * Unit tests for methods of {@link com.gildedrose.product.category.AgedBrie}
+ * which been moved to their own test classes.
+ */
+class AgedBrieTest extends BaseTest{
+
+    @Test
+    void lowerQualityAndUpQuantityByOne() {
+
+        // given
+        final int sellIn  = 2;
+        final int quality = 2;
+        final EncapsulatedItem item = createItem(Articles.AGED_BRIE.getArticle(), sellIn, quality);
+
+        // when
+        updateQuality(item);
+
+        // then
+        assertAll(
+                () -> assertEquals(sellIn -1,  item.getSellIn()),
+                () -> assertEquals(quality + 1,  item.getQuality())
+        );
+    }
+
+    @Test
+    void increaseQualityToDouble() {
+
+        // given
+        final int sellIn  = 0;
+        final int quality = 2;
+        final EncapsulatedItem item = createItem(Articles.AGED_BRIE.getArticle(), sellIn, quality);
+
+        // when
+        updateQuality(item);
+
+        // then
+        assertEquals(quality + 2,  item.getQuality());
+    }
+
+    @Test
+    void tryUpdateQualityAboveMax() {
+
+        // given
+        final int sellIn  = 2;
+        final int quality = 50;
+        final EncapsulatedItem item = createItem(Articles.AGED_BRIE.getArticle(), sellIn, quality);
+        // when
+        updateQuality(item);
+
+        // then
+        assertEquals(50,  item.getQuality(), "The Quality of an item is never more than 50");
+    }
+
+    @Test
+    void toStringEncapsulateItem() {
+        // given
+        final int sellIn  = 2;
+        final int quality = 2;
+        final EncapsulatedItem item = createItem(Articles.AGED_BRIE.getArticle(), sellIn, quality);
+        // when
+        updateQuality(item);
+        // then
+        assertEquals("Aged Brie, " + (sellIn - 1) + ", " + (quality + 1),  item.toString());
+    }
+
+    @Test
+    void checkNullItems() {
+        // given
+        final int sellIn  = 2;
+        final int quality = 2;
+        final EncapsulatedItem item = createItem(Articles.AGED_BRIE.getArticle(), sellIn, quality);
+        // when
+        // then
+        assertThrows(NullPointerException.class, () -> updateQuality(item, null));
+    }
+
+    @Test
+    void checkNullItemsInsideArray() {
+        // given
+        // when
+        // then
+        assertThrows(NullPointerException.class, () -> updateQuality((EncapsulatedItem) null));
+    }
+
+}

src/test/java/com/gildedrose/BackStagePassTest.java

@@ -0,0 +1,87 @@
+package com.gildedrose;
+
+import com.gildedrose.utils.Articles;
+import com.gildedrose.utils.EncapsulatedItem;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/**
+ * Unit tests for methods of {@link com.gildedrose.product.category.BackStagePass}
+ * which been moved to their own test classes.
+ */
+public class BackStagePassTest extends BaseTest{
+
+    @Test
+    void lowerQualityAndUpQuantityByOne() {
+
+        // given
+        final int sellIn  = 15;
+        final int quality = 3;
+        final EncapsulatedItem item = createItem(Articles.TAFKAL_80ETC.getArticle(), sellIn, quality);
+
+        // when
+        updateQuality(item);
+
+        // then
+        assertEquals(quality + 1,  item.getQuality());
+    }
+    @Test
+    void increaseQualityToDouble() {
+
+        // given
+        final int sellIn  = 9;
+        final int quality = 3;
+        final EncapsulatedItem item = createItem(Articles.TAFKAL_80ETC.getArticle(), sellIn, quality);
+
+        // when
+        updateQuality(item);
+
+        // then
+        assertEquals(quality + 2,  item.getQuality());
+    }
+    @Test
+    void dropAfterConcert() {
+
+        // given
+        final int sellIn  = 0;
+        final int quality = 3;
+        final EncapsulatedItem item = createItem(Articles.TAFKAL_80ETC.getArticle(), sellIn, quality);
+
+        // when
+        updateQuality(item);
+
+        // then
+        assertEquals(sellIn,  item.getQuality());
+    }
+
+    @Test
+    void increaseQualityToDoubleByThree() {
+
+        // given
+        final int sellIn  = 2;
+        final int quality = 2;
+        final EncapsulatedItem item = createItem(Articles.TAFKAL_80ETC.getArticle(), sellIn, quality);
+
+        // when
+        updateQuality(item);
+
+        // then
+        assertEquals(quality + 3,  item.getQuality());
+    }
+
+    @Test
+    void tryUpdateQualityAboveMax() {
+
+        // given
+        final int sellIn  = 5;
+        final int quality = 50;
+        final EncapsulatedItem item = createItem(Articles.AGED_BRIE.getArticle(), sellIn, quality);
+
+        // when
+        updateQuality(item);
+
+        // then
+        assertEquals(50,  item.getQuality(), "The Quality of an item is never more than 50");
+    }
+}

src/test/java/com/gildedrose/BaseTest.java

@@ -0,0 +1,28 @@
+package com.gildedrose;
+
+import com.gildedrose.utils.EncapsulatedItem;
+import com.gildedrose.utils.EncapsulateItemBuilder;
+
+public class BaseTest {
+
+    /**
+     * Create a {@link EncapsulatedItem} object given the {@code code}, {@code sellIn} and {@code quality}.
+     * @param name The name of the product.
+     * @param sellIn  The number of days we have to sell the item
+     * @param quality The value which denotes how valuable the item is
+     */
+    protected EncapsulatedItem createItem(final String name, final int sellIn, final int quality){
+        return new EncapsulateItemBuilder()
+                .named(name)
+                .ofQuality(quality)
+                .toSellIn(sellIn)
+                .build();
+    }
+    /**
+     * Create the instance of {@link GildedRose} and update the Quality of the {@code items}
+     */
+    protected void updateQuality(final EncapsulatedItem...items){
+        new GildedRose(items).updateQuality();
+    }
+
+}

src/test/java/com/gildedrose/ConjuredTest.java

@@ -0,0 +1,65 @@
+package com.gildedrose;
+
+import com.gildedrose.utils.Articles;
+import com.gildedrose.utils.EncapsulatedItem;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertAll;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/**
+ * Unit tests for methods of {@link com.gildedrose.product.category.Conjured}
+ * which been moved to their own test classes.
+ */
+class ConjuredTest extends BaseTest{
+
+    @Test
+    void lowerQualityByTwoAndUpQuantityByOne() {
+
+        // given
+        final int sellIn  = 4;
+        final int quality = 4;
+        final EncapsulatedItem item = createItem(Articles.CONJURED.getArticle(), sellIn, quality);
+
+        // when
+        updateQuality(item);
+
+        // then
+        assertAll(
+                () -> assertEquals(sellIn -1,  item.getSellIn()),
+                () -> assertEquals(quality - 2,  item.getQuality())
+        );
+    }
+
+    @Test
+    void increaseQualityToDouble() {
+
+        // given
+        final int sellIn  = 0;
+        final int quality = 2;
+        final EncapsulatedItem item = createItem(Articles.AGED_BRIE.getArticle(), sellIn, quality);
+
+        // when
+        updateQuality(item);
+
+        // then
+        assertEquals(quality + 2,  item.getQuality());
+    }
+
+    @Test
+    void tryUpdateQualityAboveMax() {
+
+        // given
+        final int sellIn  = 4;
+        final int quality = 50;
+        final EncapsulatedItem item = createItem(Articles.AGED_BRIE.getArticle(), sellIn, quality);
+
+        // when
+        updateQuality(item);
+
+        // then
+        assertEquals(50,  item.getQuality(), "The Quality of an item is never more than 50");
+    }
+
+
+}

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("foo", app.items[0].name);
-    }
-
-}

src/test/java/com/gildedrose/LegendaryTest.java

@@ -0,0 +1,63 @@
+package com.gildedrose;
+
+import com.gildedrose.utils.Articles;
+import com.gildedrose.utils.EncapsulatedItem;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertAll;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/**
+ * Unit tests for methods of {@link com.gildedrose.product.category.Legendary}
+ * which been moved to their own test classes.
+ */
+class LegendaryTest extends BaseTest{
+
+    @Test
+    void tryLowerQualityAndUpQuantityByOne() {
+
+        // given
+        final int sellIn  = 2;
+        final int quality = 2;
+        final EncapsulatedItem item = createItem(Articles.SULFURAS.getArticle(), sellIn, quality);
+
+        // when
+        updateQuality(item);
+
+        // then
+        assertAll(
+                () -> assertEquals(sellIn,  item.getSellIn()),
+                () -> assertEquals(quality,  item.getQuality())
+        );
+    }
+
+    @Test
+    void increaseQualityToDouble() {
+
+        // given
+        final int sellIn  = 4;
+        final int quality = 80;
+        final EncapsulatedItem item = createItem(Articles.SULFURAS.getArticle(), sellIn, quality);
+
+        // when
+        updateQuality(item);
+
+        // then
+        assertEquals(quality,  item.getQuality());
+    }
+
+    @Test
+    void tryIncreaseQuality() {
+
+        // given
+        final int sellIn  = -1;
+        final int quality = 80;
+        final EncapsulatedItem item = createItem(Articles.SULFURAS.getArticle(), sellIn, quality);
+
+        // when
+        updateQuality(item);
+
+        // then
+        assertEquals(quality,  item.getQuality());
+    }
+}

src/test/java/com/gildedrose/TexttestFixture.java

@@ -1,20 +1,13 @@
 package com.gildedrose;
 
+import com.gildedrose.utils.EncapsulatedItem;
+import com.gildedrose.utils.EncapsulateItemBuilder;
+
 public class TexttestFixture {
     public static void main(String[] args) {
         System.out.println("OMGHAI!");
 
-        Item[] items = new Item[] {
-                new Item("+5 Dexterity Vest", 10, 20), //
-                new Item("Aged Brie", 2, 0), //
-                new Item("Elixir of the Mongoose", 5, 7), //
-                new Item("Sulfuras, Hand of Ragnaros", 0, 80), //
-                new Item("Sulfuras, Hand of Ragnaros", -1, 80),
-                new Item("Backstage passes to a TAFKAL80ETC concert", 15, 20),
-                new Item("Backstage passes to a TAFKAL80ETC concert", 10, 49),
-                new Item("Backstage passes to a TAFKAL80ETC concert", 5, 49),
-                // this conjured item does not work properly yet
-                new Item("Conjured Mana Cake", 3, 6) };
+        final EncapsulatedItem[] items = buildItems();
 
         GildedRose app = new GildedRose(items);
 
@@ -26,7 +19,7 @@ public class TexttestFixture {
         for (int i = 0; i < days; i++) {
             System.out.println("-------- day " + i + " --------");
             System.out.println("name, sellIn, quality");
-            for (Item item : items) {
+            for (EncapsulatedItem item : items) {
                 System.out.println(item);
             }
             System.out.println();
@@ -34,4 +27,18 @@ public class TexttestFixture {
         }
     }
 
+    private static EncapsulatedItem[] buildItems() {
+        return new EncapsulatedItem[] {
+                new EncapsulateItemBuilder().named("+5 Dexterity Vest").toSellIn(10).ofQuality(20).build(),
+                new EncapsulateItemBuilder().named("Aged Brie").toSellIn(2).ofQuality(0).build(),
+                new EncapsulateItemBuilder().named("Elixir of the Mongoose").toSellIn(5).ofQuality(7).build(),
+                new EncapsulateItemBuilder().named("Sulfuras, Hand of Ragnaros").toSellIn(0).ofQuality(80).build(),
+                new EncapsulateItemBuilder().named("Sulfuras, Hand of Ragnaros").toSellIn(-1).ofQuality(80).build(),
+                new EncapsulateItemBuilder().named("Backstage passes to a TAFKAL80ETC concert").toSellIn(15).ofQuality(20).build(),
+                new EncapsulateItemBuilder().named("Backstage passes to a TAFKAL80ETC concert").toSellIn(10).ofQuality(49).build(),
+                new EncapsulateItemBuilder().named("Backstage passes to a TAFKAL80ETC concert").toSellIn(5).ofQuality(49).build(),
+                new EncapsulateItemBuilder().named("Conjured Mana Cake").toSellIn(3).ofQuality(6).build(),};
+
+    }
+
 }