CardDeck 클래스 및 테스트 추가

- 블랙잭 게임을 위한 `CardDeck` 클래스를 추가하였으며, 이는 카드 덱 생성, 카드 섞기, 카드 뽑기 등의 기능 포함하고 있음.
- `CardDeck`의 기능을 보장하기 위한 테스트를 추가하였음. 이에는 덱 생성, 섞기, 카드 뽑기 등의 상황에 대한 테스트가 포함됨.

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

@@ -0,0 +1,47 @@
+package io.github.gunkim.blackjack.domain;
+
+import java.util.*;
+
+public class CardDeck {
+    private static final int DEFAULT_CARD_SIZE = 52;
+
+    private final ArrayDeque<Card> cards;
+
+    CardDeck(Collection<Card> cards) {
+        validateCards(cards);
+        this.cards = new ArrayDeque<>(cards);
+    }
+
+    public static CardDeck shuffle() {
+        List<Card> shuffledCards = new ArrayList<>(Card.distinctCards());
+
+        Collections.shuffle(shuffledCards);
+        return new CardDeck(shuffledCards);
+    }
+
+    public Card draw() {
+        if (cards.isEmpty()) {
+            throw new IllegalStateException("No more cards in the deck");
+        }
+        return cards.remove();
+    }
+
+    private void validateCards(Collection<Card> cards) {
+        Objects.requireNonNull(cards, "cards must not be null");
+        checkForDuplicateCards(cards);
+        validateCardDeckSize(cards);
+    }
+
+    private void checkForDuplicateCards(Collection<Card> cards) {
+        var containsDuplicateCards = new HashSet<>(cards).size() != cards.size();
+        if (containsDuplicateCards) {
+            throw new IllegalArgumentException("cards must not contain duplicate cards");
+        }
+    }
+
+    private void validateCardDeckSize(Collection<Card> cards) {
+        if (cards.size() != DEFAULT_CARD_SIZE) {
+            throw new IllegalArgumentException(String.format("cards must contain %d cards", DEFAULT_CARD_SIZE));
+        }
+    }
+}

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

@@ -0,0 +1,77 @@
+package io.github.gunkim.blackjack.domain;
+
+import io.github.gunkim.blackjack.domain.vo.CardNumber;
+import io.github.gunkim.blackjack.domain.vo.CardSuit;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.IntStream;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+@DisplayName("카드 덱은")
+class CardDeckTest {
+    @Test
+    @DisplayName("생성된다")
+    void shouldCreateCardDeck() {
+        List<Card> cards = Card.distinctCards();
+
+        assertDoesNotThrow(() -> new CardDeck(cards));
+    }
+
+    @Test
+    @DisplayName("섞인 채로 생성된다")
+    void shouldCreateShuffledDeck() {
+        CardDeck cardDeck = CardDeck.shuffle();
+
+        assertNotNull(cardDeck);
+    }
+
+    @Test
+    @DisplayName("중복된 카드가 없을 경우 생성된다")
+    void shouldCreateCardDeckWhenNotDuplicatedCards() {
+        List<Card> cards = Card.distinctCards();
+
+        assertDoesNotThrow(() -> new CardDeck(cards));
+    }
+
+    @Test
+    @DisplayName("중복된 카드가 있을 경우 생성되지 않는다")
+    void shouldFailToCreateCardDeckWhenDuplicatedCards() {
+        List<Card> cards = new ArrayList<>(Card.distinctCards());
+        cards.removeLast();
+        cards.add(cards.get(0));
+
+        assertThrows(IllegalArgumentException.class, () -> new CardDeck(cards));
+    }
+
+    @Test
+    @DisplayName("카드가 52장이 아닐 경우 예외가 발생한다")
+    void shouldThrowExceptionWhenCardCountIsNot52() {
+        List<Card> cards = List.of(new Card(CardSuit.CLUBS, CardNumber.A));
+
+        String actualErrorMessage = assertThrows(IllegalArgumentException.class, () -> new CardDeck(cards)).getMessage();
+        assertEquals(actualErrorMessage, "cards must contain 52 cards");
+    }
+
+    @Test
+    @DisplayName("덱에 카드가 남아 있다면 카드를 뽑을 수 있어야 한다")
+    void shouldDrawCardWhenDeckIsNotEmpty() {
+        CardDeck cardDeck = CardDeck.shuffle();
+        Card card = cardDeck.draw();
+
+        assertNotNull(card);
+    }
+
+    @Test
+    @DisplayName("덱에 카드가 비어 있다면 카드를 뽑을 수 없다")
+    void shouldThrowExceptionWhenCardDeckIsEmpty() {
+        CardDeck cardDeck = CardDeck.shuffle();
+        IntStream.range(0, 52).forEach(__ -> cardDeck.draw());
+
+        String actualErrorMessage = assertThrows(IllegalStateException.class, cardDeck::draw).getMessage();
+        assertEquals(actualErrorMessage, "No more cards in the deck");
+    }
+}