feat(recommend): 추천 팔로우 성공 로그를 커밋 후 기록한다

src/main/kotlin/kr/co/vividnext/sodalive/v2/recommend/application/RecommendedCreatorFollowService.kt

@@ -5,16 +5,27 @@ import kr.co.vividnext.sodalive.member.Member
 import kr.co.vividnext.sodalive.member.MemberRepository
 import kr.co.vividnext.sodalive.member.following.CreatorFollowing
 import kr.co.vividnext.sodalive.member.following.CreatorFollowingRepository
+import org.slf4j.LoggerFactory
 import org.springframework.stereotype.Service
 import org.springframework.transaction.annotation.Transactional
+import org.springframework.transaction.support.TransactionSynchronization
+import org.springframework.transaction.support.TransactionSynchronizationManager
 
 @Service
 class RecommendedCreatorFollowService(
     private val memberRepository: MemberRepository,
     private val creatorFollowingRepository: CreatorFollowingRepository
 ) {
+    private val log = LoggerFactory.getLogger(javaClass)
+
     @Transactional
     fun followCreators(member: Member, creatorIds: List<Long>) {
+        val startedAt = System.currentTimeMillis()
+        var savedCount = 0
+        var reactivatedCount = 0
+        var skippedCount = 0
+
+        runCatching {
             val distinctCreatorIds = creatorIds.distinct()
             val creatorById = distinctCreatorIds
                 .filter { it != member.id }
@@ -25,6 +36,7 @@ class RecommendedCreatorFollowService(
 
             distinctCreatorIds.forEach { creatorId ->
                 if (creatorId == member.id) {
+                    skippedCount += 1
                     return@forEach
                 }
 
@@ -36,6 +48,9 @@ class RecommendedCreatorFollowService(
                     if (!existingFollowing.isActive) {
                         existingFollowing.isNotify = true
                         existingFollowing.isActive = true
+                        reactivatedCount += 1
+                    } else {
+                        skippedCount += 1
                     }
                     return@forEach
                 }
@@ -46,6 +61,47 @@ class RecommendedCreatorFollowService(
                         creator = creatorById.getValue(creatorId)
                     }
                 )
+                savedCount += 1
+            }
+            distinctCreatorIds.size
+        }.onSuccess { distinctCount ->
+            afterCommit {
+                log.info(
+                    "event=recommended_creator_follow_success " +
+                        "memberId={} requestedCount={} distinctCount={} savedCount={} " +
+                        "reactivatedCount={} skippedCount={} elapsedMs={}",
+                    member.id,
+                    creatorIds.size,
+                    distinctCount,
+                    savedCount,
+                    reactivatedCount,
+                    skippedCount,
+                    System.currentTimeMillis() - startedAt
+                )
+            }
+        }.onFailure { ex ->
+            log.warn(
+                "event=recommended_creator_follow_failure memberId={} requestedCount={} distinctCount={} elapsedMs={} error={}",
+                member.id,
+                creatorIds.size,
+                creatorIds.distinct().size,
+                System.currentTimeMillis() - startedAt,
+                ex.message,
+                ex
+            )
+            throw ex
         }
     }
+
+    private fun afterCommit(action: () -> Unit) {
+        if (!TransactionSynchronizationManager.isSynchronizationActive()) {
+            action()
+            return
+        }
+        TransactionSynchronizationManager.registerSynchronization(
+            object : TransactionSynchronization {
+                override fun afterCommit() = action()
+            }
+        )
+    }
 }

src/test/kotlin/kr/co/vividnext/sodalive/v2/recommend/application/RecommendedCreatorFollowServiceTest.kt

@@ -14,16 +14,21 @@ import org.junit.jupiter.api.Assertions.assertThrows
 import org.junit.jupiter.api.Assertions.assertTrue
 import org.junit.jupiter.api.DisplayName
 import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.extension.ExtendWith
 import org.springframework.beans.factory.annotation.Autowired
 import org.springframework.boot.test.context.SpringBootTest
+import org.springframework.boot.test.system.CapturedOutput
+import org.springframework.boot.test.system.OutputCaptureExtension
 import org.springframework.dao.DataIntegrityViolationException
 import org.springframework.test.context.ContextConfiguration
 import org.springframework.transaction.annotation.Transactional
+import org.springframework.transaction.support.TransactionSynchronizationManager
 import javax.persistence.EntityManager
 
 @SpringBootTest
 @Transactional
 @ContextConfiguration(initializers = [EmbeddedRedisInitializer::class])
+@ExtendWith(OutputCaptureExtension::class)
 class RecommendedCreatorFollowServiceTest @Autowired constructor(
     private val service: RecommendedCreatorFollowService,
     private val memberRepository: MemberRepository,
@@ -32,7 +37,7 @@ class RecommendedCreatorFollowServiceTest @Autowired constructor(
 ) {
     @Test
     @DisplayName("신규 크리에이터만 팔로우 저장하고 이미 팔로우/본인 id는 서버 내부에서 제외한다")
-    fun shouldFollowOnlyNewCreatorsAndSkipExistingAndSelf() {
+    fun shouldFollowOnlyNewCreatorsAndSkipExistingAndSelf(output: CapturedOutput) {
         val member = saveMember("viewer", MemberRole.USER)
         val newCreator = saveMember("new-creator", MemberRole.CREATOR)
         val followedCreator = saveMember("followed-creator", MemberRole.CREATOR)
@@ -40,16 +45,39 @@ class RecommendedCreatorFollowServiceTest @Autowired constructor(
         entityManager.flush()
         entityManager.clear()
 
+        val beforeCount = TransactionSynchronizationManager.getSynchronizations().size
         service.followCreators(
             member = member,
             creatorIds = listOf(newCreator.id!!, followedCreator.id!!, member.id!!)
         )
         entityManager.flush()
         entityManager.clear()
+        TransactionSynchronizationManager.getSynchronizations().drop(beforeCount).forEach { it.afterCommit() }
 
         assertNotNull(creatorFollowingRepository.findByCreatorIdAndMemberId(newCreator.id!!, member.id!!))
         assertNotNull(creatorFollowingRepository.findByCreatorIdAndMemberId(followedCreator.id!!, member.id!!))
         assertEquals(2, creatorFollowingRepository.findAll().size)
+        assertTrue(output.out.contains("event=recommended_creator_follow_success"))
+        assertTrue(output.out.contains("requestedCount=3"))
+        assertTrue(output.out.contains("savedCount=1"))
+    }
+
+    @Test
+    @DisplayName("추천 크리에이터 동시 팔로우 성공 로그는 트랜잭션 커밋 후 기록한다")
+    fun shouldLogFollowSuccessAfterTransactionCommit(output: CapturedOutput) {
+        val member = saveMember("after-commit-viewer", MemberRole.USER)
+        val creator = saveMember("after-commit-creator", MemberRole.CREATOR)
+        entityManager.flush()
+        entityManager.clear()
+
+        val beforeCount = TransactionSynchronizationManager.getSynchronizations().size
+
+        service.followCreators(member = member, creatorIds = listOf(creator.id!!))
+
+        assertEquals(false, output.out.contains("event=recommended_creator_follow_success"))
+        TransactionSynchronizationManager.getSynchronizations().drop(beforeCount).forEach { it.afterCommit() }
+
+        assertTrue(output.out.contains("event=recommended_creator_follow_success"))
     }
 
     @Test
@@ -119,7 +147,7 @@ class RecommendedCreatorFollowServiceTest @Autowired constructor(
 
     @Test
     @DisplayName("존재하지 않는 id가 하나라도 포함되면 전체 실패하고 신규 저장하지 않는다")
-    fun shouldFailAllAndSaveNothingWhenAnyCreatorIdDoesNotExist() {
+    fun shouldFailAllAndSaveNothingWhenAnyCreatorIdDoesNotExist(output: CapturedOutput) {
         val member = saveMember("viewer", MemberRole.USER)
         val validCreator = saveMember("valid-creator", MemberRole.CREATOR)
         entityManager.flush()
@@ -131,6 +159,7 @@ class RecommendedCreatorFollowServiceTest @Autowired constructor(
 
         assertEquals("member.validation.creator_not_found", exception.messageKey)
         assertEquals(0, creatorFollowingRepository.findAll().size)
+        assertTrue(output.out.contains("event=recommended_creator_follow_failure"))
     }
 
     @Test