Maintenance: Quiz Service - Improve code consistency and test coverage (#115)

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>
Co-authored-by: Claude <[email protected]>

Author: 3 people

src/main/java/spring/memewikibe/application/QuizService.java

@@ -15,12 +15,12 @@
 @RequiredArgsConstructor
 @Transactional(readOnly = true)
 public class QuizService {
-    private static final int quizLimit = 10;
+    private static final int QUIZ_LIMIT = 10;
 
     private final MemeQuizRepository quizRepository;
 
     public List<QuizProblemResponse> getRandomQuizzes() {
-        return quizRepository.findRandomQuizzes(quizLimit).stream()
+        return quizRepository.findRandomQuizzes(QUIZ_LIMIT).stream()
             .map(this::toProblem)
             .toList();
     }

src/test/java/spring/memewikibe/application/QuizServiceTest.java

@@ -48,6 +48,81 @@ void tearDown() {
         then(result).hasSize(10);
         result.forEach(q -> then(q.questions()).hasSize(4));
     }
+
+    @Test
+    void 퀴즈가_10개_미만일_때_존재하는_모든_퀴즈를_반환한다() {
+        List<MemeQuiz> quizzes = IntStream.rangeClosed(1, 5)
+            .mapToObj(i -> MemeQuiz.builder()
+                .question("문제 " + i)
+                .option1("보기1")
+                .option2("보기2")
+                .option3("보기3")
+                .option4("보기4")
+                .answer(2)
+                .imageUrl("https://example.com/" + i + ".jpg")
+                .build())
+            .toList();
+        quizRepository.saveAll(quizzes);
+
+        List<QuizProblemResponse> result = quizService.getRandomQuizzes();
+
+        then(result).hasSize(5);
+        result.forEach(q -> then(q.questions()).hasSize(4));
+    }
+
+    @Test
+    void 퀴즈가_정확히_10개일_때_모든_퀴즈를_반환한다() {
+        List<MemeQuiz> quizzes = IntStream.rangeClosed(1, 10)
+            .mapToObj(i -> MemeQuiz.builder()
+                .question("문제 " + i)
+                .option1("보기1")
+                .option2("보기2")
+                .option3("보기3")
+                .option4("보기4")
+                .answer(3)
+                .imageUrl("https://example.com/" + i + ".jpg")
+                .build())
+            .toList();
+        quizRepository.saveAll(quizzes);
+
+        List<QuizProblemResponse> result = quizService.getRandomQuizzes();
+
+        then(result).hasSize(10);
+        result.forEach(q -> then(q.questions()).hasSize(4));
+    }
+
+    @Test
+    void 퀴즈가_없을_때_빈_리스트를_반환한다() {
+        List<QuizProblemResponse> result = quizService.getRandomQuizzes();
+
+        then(result).isEmpty();
+    }
+
+    @Test
+    void 각_퀴즈의_정답이_올바르게_매핑된다() {
+        MemeQuiz quiz = MemeQuiz.builder()
+            .question("정답이 3번인 문제")
+            .option1("오답1")
+            .option2("오답2")
+            .option3("정답")
+            .option4("오답3")
+            .answer(3)
+            .imageUrl("https://example.com/test.jpg")
+            .build();
+        quizRepository.save(quiz);
+
+        List<QuizProblemResponse> result = quizService.getRandomQuizzes();
+
+        then(result).hasSize(1);
+        QuizProblemResponse response = result.get(0);
+        then(response.question()).isEqualTo("정답이 3번인 문제");
+        then(response.image()).isEqualTo("https://example.com/test.jpg");
+        then(response.questions()).hasSize(4);
+        then(response.questions().get(0).isRight()).isFalse();
+        then(response.questions().get(1).isRight()).isFalse();
+        then(response.questions().get(2).isRight()).isTrue();
+        then(response.questions().get(3).isRight()).isFalse();
+    }
 }