Create abstract GildedRoseItem to refresh item state

Java/src/main/java/com/gildedrose/Quality.java

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+package com.gildedrose;
+
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.Setter;
+import lombok.ToString;
+
+@ToString
+@EqualsAndHashCode
+public class Quality {
+  static final int DEFAULT_MAX_QUALITY = 50;
+  static final int DEFAULT_MIN_QUALITY = 0;
+
+  private final int maximumQuality;
+  private final int minimumValue;
+  @Getter @Setter private int value;
+
+  private Quality(int maximumQuality, int minimumValue, int value) {
+    this.maximumQuality = maximumQuality;
+    this.minimumValue = minimumValue;
+    this.value = value;
+  }
+
+  public static Quality create(int value) {
+    return Quality.create(value, DEFAULT_MAX_QUALITY);
+  }
+
+  public static Quality create(int value, int maximumQuality) {
+    return new Quality(maximumQuality, DEFAULT_MIN_QUALITY, value);
+  }
+
+  public Quality copy() {
+    return new Quality(maximumQuality, minimumValue, value);
+  }
+
+  public void decrement() {
+    if (this.value - 1 >= this.minimumValue) {
+      this.value--;
+    } else {
+      this.value = this.minimumValue;
+    }
+  }
+
+  public void increment() {
+    if (this.value + 1 <= this.maximumQuality) {
+      this.value++;
+    } else {
+      this.value = this.maximumQuality;
+    }
+  }
+}

Java/src/main/java/com/gildedrose/SellIn.java

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+package com.gildedrose;
+
+import lombok.EqualsAndHashCode;
+import lombok.ToString;
+
+@ToString
+@EqualsAndHashCode
+public class SellIn {
+
+  private int daysLeftToSell;
+
+  private SellIn(int days) {
+    this.daysLeftToSell = days;
+  }
+
+  public static SellIn create(int daysLeftToSell) {
+    return new SellIn(daysLeftToSell);
+  }
+
+  public void decrement() {
+    this.daysLeftToSell--;
+  }
+
+  public boolean daysLeftUntilIsOverAreLessThan(int days) {
+    return this.daysLeftToSell < days;
+  }
+
+  public boolean isOver() {
+    return this.daysLeftToSell <= 0;
+  }
+}

Java/src/main/java/com/gildedrose/items/GildedRoseItem.java

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+package com.gildedrose.items;
+
+import com.gildedrose.Item;
+import com.gildedrose.Quality;
+import com.gildedrose.SellIn;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+
+@Getter
+@EqualsAndHashCode
+public abstract class GildedRoseItem {
+
+  private final String name;
+  private final Quality quality;
+  private final SellIn sellIn;
+  private final boolean conjured;
+
+  protected GildedRoseItem(Item item) {
+    this(item.name, SellIn.create(item.sellIn), Quality.create(item.quality), false);
+  }
+
+  protected GildedRoseItem(String name, SellIn sellIn, Quality quality, boolean conjured) {
+    this.name = name;
+    this.sellIn = sellIn;
+    this.quality = quality;
+    this.conjured = conjured;
+  }
+
+  public void refreshState() {
+    this.getSellIn().decrement();
+    Quality nextQuality = this.nextQuality(this.getQuality());
+    if (this.isConjured()) {
+      nextQuality = this.nextQuality(nextQuality);
+    }
+    this.getQuality().setValue(nextQuality.getValue());
+  }
+
+  protected abstract Quality nextQuality(Quality previous);
+}

Java/src/test/java/com/gildedrose/items/GildedRoseItemTest.java

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+package com.gildedrose.items;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.doCallRealMethod;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import com.gildedrose.Quality;
+import com.gildedrose.SellIn;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+
+class GildedRoseItemTest {
+
+  @Nested
+  class refreshState {
+    GildedRoseItem item;
+
+    @BeforeEach
+    void setUp() {
+      item = mock(GildedRoseItem.class);
+      when(item.getSellIn()).thenReturn(SellIn.create(0));
+      when(item.getQuality()).thenReturn(Quality.create(0));
+      when(item.nextQuality(Quality.create(0))).thenReturn(Quality.create(10));
+      when(item.nextQuality(Quality.create(10))).thenReturn(Quality.create(5));
+      doCallRealMethod().when(item).refreshState();
+    }
+
+    @Test
+    void should_decrement_sellIn_in_one() {
+      item.refreshState();
+
+      assertThat(item.getSellIn()).isEqualTo(SellIn.create(-1));
+    }
+
+    @Test
+    void should_update_quality_using_nextQuality() {
+      item.refreshState();
+
+      assertThat(item.getQuality()).isEqualTo(Quality.create(10));
+    }
+
+    @Test
+    void should_update_quality_twice_when_is_conjured() {
+      when(item.isConjured()).thenReturn(Boolean.TRUE);
+
+      item.refreshState();
+
+      assertThat(item.getQuality()).isEqualTo(Quality.create(5));
+    }
+  }
+}