refactor(test): 테스트 코드에서 null 처리 개선

- 응답 본문에서 null 체크를 추가하여 안정성 향상
- 불필요한 변수 선언 제거로 코드 간결화

Author: hyujikoh

apps/commerce-api/src/test/java/com/loopers/interfaces/api/RankingV1ApiE2ETest.java

@@ -71,7 +71,6 @@ class RankingV1ApiE2ETest {
     @Autowired
     private CacheKeyGenerator cacheKeyGenerator;
 
-    private Long testBrandId;
     private final List<Long> testProductIds = new ArrayList<>();
     private LocalDate today;
 
@@ -80,7 +79,7 @@ void setUp() {
         databaseCleanUp.truncateAllTables();
         redisCleanUp.truncateAll();
         testProductIds.clear();
-        testBrandId = null;
+        Long testBrandId = null;
 
         today = LocalDate.now();
 
@@ -141,9 +140,9 @@ void should_return_products_in_ranking_order() {
             assertAll(
                     () -> assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK),
                     () -> assertThat(Objects.requireNonNull(response.getBody()).data().content()).hasSize(3),
-                    () -> assertThat(response.getBody().data().content().get(0).productId()).isEqualTo(product1),
+                    () -> assertThat(Objects.requireNonNull(response.getBody()).data().content().get(0).productId()).isEqualTo(product1),
                     () -> assertThat(response.getBody().data().content().get(2).productId()).isEqualTo(product2),
-                    () -> assertThat(response.getBody().data().content().get(1).productId()).isEqualTo(product3)
+                    () -> assertThat(Objects.requireNonNull(response.getBody()).data().content().get(1).productId()).isEqualTo(product3)
             );
         }
 
@@ -165,7 +164,7 @@ void should_return_empty_when_no_ranking_data() {
             assertAll(
                     () -> assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK),
                     () -> assertThat(Objects.requireNonNull(response.getBody()).data().content()).isEmpty(),
-                    () -> assertThat(response.getBody().data().totalElements()).isEqualTo(0)
+                    () -> assertThat(Objects.requireNonNull(response.getBody()).data().totalElements()).isEqualTo(0)
             );
         }
 
@@ -197,10 +196,10 @@ void should_paginate_ranking_results() {
             assertAll(
                     () -> assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK),
                     () -> assertThat(Objects.requireNonNull(response.getBody()).data().content()).hasSize(2),
-                    () -> assertThat(response.getBody().data().totalElements()).isEqualTo(5),
-                    () -> assertThat(response.getBody().data().totalPages()).isEqualTo(3),
-                    () -> assertThat(response.getBody().data().first()).isTrue(),
-                    () -> assertThat(response.getBody().data().last()).isFalse()
+                    () -> assertThat(Objects.requireNonNull(response.getBody()).data().totalElements()).isEqualTo(5),
+                    () -> assertThat(Objects.requireNonNull(response.getBody()).data().totalPages()).isEqualTo(3),
+                    () -> assertThat(Objects.requireNonNull(response.getBody()).data().first()).isTrue(),
+                    () -> assertThat(Objects.requireNonNull(response.getBody()).data().last()).isFalse()
             );
         }
 
@@ -229,7 +228,7 @@ void should_return_ranking_for_specific_date() {
             assertAll(
                     () -> assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK),
                     () -> assertThat(Objects.requireNonNull(response.getBody()).data().content()).hasSize(1),
-                    () -> assertThat(response.getBody().data().content().get(0).productId()).isEqualTo(product1)
+                    () -> assertThat(Objects.requireNonNull(response.getBody()).data().content().get(0).productId()).isEqualTo(product1)
             );
         }
     }
@@ -263,7 +262,7 @@ void should_fallback_to_yesterday_when_today_is_empty() {
             assertAll(
                     () -> assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK),
                     () -> assertThat(Objects.requireNonNull(response.getBody()).data().content()).hasSize(1),
-                    () -> assertThat(response.getBody().data().content().get(0).productId()).isEqualTo(product1)
+                    () -> assertThat(Objects.requireNonNull(response.getBody()).data().content().get(0).productId()).isEqualTo(product1)
             );
         }
 
@@ -325,9 +324,9 @@ void should_include_ranking_info_for_ranked_product() {
             assertAll(
                     () -> assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK),
                     () -> assertThat(Objects.requireNonNull(response.getBody()).data().productId()).isEqualTo(productId),
-                    () -> assertThat(response.getBody().data().ranking()).isNotNull(),
-                    () -> assertThat(response.getBody().data().ranking().rank()).isEqualTo(1L),
-                    () -> assertThat(response.getBody().data().ranking().score()).isGreaterThan(0)
+                    () -> assertThat(Objects.requireNonNull(response.getBody()).data().ranking()).isNotNull(),
+                    () -> assertThat(Objects.requireNonNull(response.getBody()).data().ranking().rank()).isEqualTo(1L),
+                    () -> assertThat(Objects.requireNonNull(response.getBody()).data().ranking().score()).isGreaterThan(0)
             );
         }
 
@@ -350,7 +349,7 @@ void should_have_null_ranking_for_unranked_product() {
             assertAll(
                     () -> assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK),
                     () -> assertThat(Objects.requireNonNull(response.getBody()).data().productId()).isEqualTo(productId),
-                    () -> assertThat(response.getBody().data().ranking()).isNull()
+                    () -> assertThat(Objects.requireNonNull(response.getBody()).data().ranking()).isNull()
             );
         }
 
@@ -382,8 +381,8 @@ void should_return_correct_rank_among_multiple_products() {
             assertAll(
                     () -> assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK),
                     () -> assertThat(Objects.requireNonNull(response.getBody()).data().productId()).isEqualTo(product2),
-                    () -> assertThat(response.getBody().data().ranking()).isNotNull(),
-                    () -> assertThat(response.getBody().data().ranking().rank()).isEqualTo(2L)
+                    () -> assertThat(Objects.requireNonNull(response.getBody()).data().ranking()).isNotNull(),
+                    () -> assertThat(Objects.requireNonNull(response.getBody()).data().ranking().rank()).isEqualTo(2L)
             );
         }
     }
@@ -424,7 +423,7 @@ void should_accumulate_scores_for_same_product() {
             assertAll(
                     () -> assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK),
                     () -> assertThat(Objects.requireNonNull(response.getBody()).data().ranking()).isNotNull(),
-                    () -> assertThat(response.getBody().data().ranking().score()).isGreaterThanOrEqualTo(5.0)
+                    () -> assertThat(Objects.requireNonNull(response.getBody()).data().ranking().score()).isGreaterThanOrEqualTo(5.0)
             );
         }
     }

apps/commerce-streamer/src/test/java/com/loopers/integration/MetricsEventProcessingIntegrationTest.java

@@ -11,7 +11,6 @@
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.kafka.core.KafkaTemplate;
-import org.springframework.transaction.annotation.Transactional;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.loopers.domain.event.EventRepository;