블랙잭 게임에서 Dealer 및 Player 클래스 추가

blackjack/src/main/java/io/github/gunkim/blackjack/domain/CardDeck.java

@@ -1,6 +1,7 @@
 package io.github.gunkim.blackjack.domain;
 
 import java.util.*;
+import java.util.stream.IntStream;
 
 public class CardDeck {
     private static final int DEFAULT_CARD_SIZE = 52;
@@ -26,6 +27,12 @@ public Card draw() {
         return cards.remove();
     }
 
+    public List<Card> draw(int quantity) {
+        return IntStream.range(0, quantity)
+                .mapToObj(__ -> draw())
+                .toList();
+    }
+
     private void validateCards(Collection<Card> cards) {
         Objects.requireNonNull(cards, "cards must not be null");
         checkForDuplicateCards(cards);

blackjack/src/main/java/io/github/gunkim/blackjack/domain/Dealer.java

@@ -0,0 +1,10 @@
+package io.github.gunkim.blackjack.domain;
+
+public record Dealer(CardDeck deck) {
+    //TODO: 최초 블랙잭 시작 시 딜러는 플레이어에게 2장의 카드를 나눠줘야 함을 변수로 나타냄. 더 적절한 네이밍이 필요함.
+    public static final int CARD_DEAL = 2;
+
+    public Player deal() {
+        return new Player(deck.draw(CARD_DEAL));
+    }
+}

blackjack/src/main/java/io/github/gunkim/blackjack/domain/Player.java

@@ -0,0 +1,20 @@
+package io.github.gunkim.blackjack.domain;
+
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Objects;
+import java.util.Set;
+
+public class Player {
+    //TODO: 일급 컬렉션 및 별도의 객체로 분리될 수 있을 것 같음. 혹은 CardDeck이 이 역할을 어느정도 할 수도 있음.
+    private final Set<Card> cards;
+
+    public Player(Collection<Card> cards) {
+        Objects.requireNonNull(cards, "cards must not be null");
+
+        if (cards.size() != Dealer.CARD_DEAL) {
+            throw new IllegalArgumentException("Player must have exactly %d cards".formatted(Dealer.CARD_DEAL));
+        }
+        this.cards = new HashSet<>(cards);
+    }
+}

blackjack/src/test/java/io/github/gunkim/blackjack/domain/DealerTest.java

@@ -0,0 +1,25 @@
+package io.github.gunkim.blackjack.domain;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+@DisplayName("딜러는")
+class DealerTest {
+    private Dealer sut;
+
+    @BeforeEach
+    void setup() {
+        var dummyCardDeck = new CardDeck(Card.distinctCards());
+        this.sut = new Dealer(dummyCardDeck);
+    }
+
+    @Test
+    @DisplayName("플레이어에게 카드를 나눠준다")
+    void shouldDeal() {
+        var player = sut.deal();
+        assertNotNull(player);
+    }
+}