fix(coupon): 캔 쿠폰 사용 트랜잭션을 보강한다

src/main/kotlin/kr/co/vividnext/sodalive/can/coupon/CanCouponService.kt

@@ -131,6 +131,7 @@ class CanCouponService(
         }
     }
 
+    @Transactional
     fun useCanCoupon(couponNumber: String, memberId: Long): String {
         val member = memberRepository.findByIdOrNull(id = memberId)
             ?: throw SodaException(messageKey = "common.error.bad_credentials")

src/test/kotlin/kr/co/vividnext/sodalive/can/coupon/CanCouponServiceIntegrationTest.kt

@@ -0,0 +1,111 @@
+package kr.co.vividnext.sodalive.can.coupon
+
+import kr.co.vividnext.sodalive.member.Member
+import kr.co.vividnext.sodalive.member.MemberRepository
+import kr.co.vividnext.sodalive.member.auth.Auth
+import kr.co.vividnext.sodalive.support.EmbeddedRedisInitializer
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.DisplayName
+import org.junit.jupiter.api.Test
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.boot.test.context.SpringBootTest
+import org.springframework.test.annotation.DirtiesContext
+import org.springframework.test.context.ContextConfiguration
+import org.springframework.transaction.annotation.Propagation
+import org.springframework.transaction.annotation.Transactional
+import org.springframework.transaction.support.TransactionTemplate
+import java.time.LocalDateTime
+import javax.persistence.EntityManager
+
+@SpringBootTest(
+    properties = [
+        "spring.cache.type=none",
+        "spring.datasource.url=jdbc:h2:mem:can-coupon-service-integration;" +
+            "MODE=MySQL;DATABASE_TO_UPPER=false;NON_KEYWORDS=VALUE;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE"
+    ]
+)
+@ContextConfiguration(initializers = [EmbeddedRedisInitializer::class])
+@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_CLASS)
+@Transactional(propagation = Propagation.NOT_SUPPORTED)
+class CanCouponServiceIntegrationTest @Autowired constructor(
+    private val service: CanCouponService,
+    private val memberRepository: MemberRepository,
+    private val couponNumberRepository: CanCouponNumberRepository,
+    private val transactionTemplate: TransactionTemplate,
+    private val entityManager: EntityManager
+) {
+    @Test
+    @DisplayName("쿠폰 사용은 OSIV off 환경의 실제 서비스 호출 경로에서 lazy auth 접근까지 완료된다")
+    fun shouldUseCouponThroughTransactionalServiceProxyWhenOpenInViewIsDisabled() {
+        val fixture = createAuthenticatedMemberAndCouponFixture()
+
+        service.useCanCoupon(couponNumber = fixture.couponNumber, memberId = fixture.memberId)
+
+        val result = transactionTemplate.execute {
+            val member = memberRepository.findById(fixture.memberId).orElseThrow()
+            val couponNumber = couponNumberRepository.findByCouponNumber(fixture.couponNumber)!!
+
+            CouponUseResult(
+                rewardCan = member.pgRewardCan,
+                usedMemberId = couponNumber.member!!.id!!
+            )
+        }!!
+
+        assertEquals(300, result.rewardCan)
+        assertEquals(fixture.memberId, result.usedMemberId)
+    }
+
+    private fun createAuthenticatedMemberAndCouponFixture(): Fixture {
+        return transactionTemplate.execute {
+            val member = Member(
+                email = "can-coupon-osiv@test.com",
+                password = "password",
+                nickname = "can-coupon-osiv"
+            )
+            entityManager.persist(member)
+
+            val auth = Auth(
+                name = "테스트",
+                birth = "19900101",
+                uniqueCi = "can-coupon-osiv-ci",
+                di = "can-coupon-osiv-di",
+                gender = 1
+            )
+            auth.member = member
+            entityManager.persist(auth)
+
+            val coupon = CanCoupon(
+                couponName = "OSIV 회귀 테스트 쿠폰",
+                couponType = CouponType.CAN,
+                can = 300,
+                couponCount = 1,
+                validity = LocalDateTime.now().plusDays(1),
+                isActive = true,
+                isMultipleUse = false
+            )
+            entityManager.persist(coupon)
+
+            val couponNumber = CanCouponNumber("OSIVCOUPON1234")
+            couponNumber.canCoupon = coupon
+            entityManager.persist(couponNumber)
+
+            entityManager.flush()
+            val fixture = Fixture(
+                memberId = member.id!!,
+                couponNumber = couponNumber.couponNumber
+            )
+            entityManager.clear()
+            fixture
+        }!!
+    }
+
+    private data class Fixture(
+        val memberId: Long,
+        val couponNumber: String
+    )
+
+    private data class CouponUseResult(
+        val rewardCan: Int,
+        val usedMemberId: Long
+    )
+}

src/test/kotlin/kr/co/vividnext/sodalive/can/coupon/CanCouponServiceTest.kt

@@ -19,6 +19,7 @@ import org.mockito.Mockito.never
 import org.mockito.Mockito.verify
 import org.mockito.Mockito.`when`
 import org.springframework.context.ApplicationEventPublisher
+import org.springframework.transaction.annotation.Transactional
 import java.util.Optional
 
 class CanCouponServiceTest {
@@ -110,6 +111,20 @@ class CanCouponServiceTest {
         verify(chargeService, never()).chargeByCoupon("COUPON5678", member)
     }
 
+    @Test
+    @DisplayName("쿠폰 사용은 OSIV off 환경에서도 lazy 연관을 읽을 수 있도록 트랜잭션 안에서 실행된다")
+    fun shouldRunUseCanCouponInTransaction() {
+        val method = CanCouponService::class.java.getDeclaredMethod(
+            "useCanCoupon",
+            String::class.java,
+            java.lang.Long.TYPE
+        )
+
+        val transactional = method.getAnnotation(Transactional::class.java)
+
+        assertEquals(false, transactional?.readOnly)
+    }
+
     private fun createMember(memberId: Long): Member {
         return Member(
             email = "member$memberId@test.com",