Add MonsterCard

src/main/java/database/monsterbook/MonsterCard.java

@@ -0,0 +1,17 @@
+package database.monsterbook;
+
+public record MonsterCard(int cardId, byte level) {
+
+    public MonsterCard {
+        if (cardId / 10_000 != 238) {
+            throw new IllegalArgumentException("Invalid monster card id: %d".formatted(cardId));
+        }
+        if (level < 0 || level > 5) {
+            throw new IllegalArgumentException("Invalid monster card level: %d".formatted(level));
+        }
+    }
+
+    public boolean isSpecial() {
+        return cardId / 1000 == 2388;
+    }
+}

src/test/java/database/monsterbook/MonsterCardTest.java

@@ -0,0 +1,48 @@
+package database.monsterbook;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class MonsterCardTest {
+
+    @Test
+    void invalidCardId() {
+        assertThrows(IllegalArgumentException.class, () -> new MonsterCard(123456, validLevel()));
+    }
+
+    @ParameterizedTest
+    @ValueSource(bytes = {-1, 6})
+    void invalidLevel(byte invalidLevel) {
+        assertThrows(IllegalArgumentException.class, () -> new MonsterCard(validCardId(), invalidLevel));
+    }
+
+    @Test
+    public void createValidCard() {
+        assertDoesNotThrow(() -> new MonsterCard(validCardId(), validLevel()));
+    }
+
+    @Test
+    void specialCardIsSpecial() {
+        var specialCard = new MonsterCard(2388000, validLevel());
+
+        assertTrue(specialCard.isSpecial());
+    }
+
+    @Test
+    void normalCardIsNotSpecial() {
+        var normalCard = new MonsterCard(2381234, validLevel());
+
+        assertFalse(normalCard.isSpecial());
+    }
+
+    private int validCardId() {
+        return 2380000;
+    }
+
+    private byte validLevel() {
+        return 1;
+    }
+}