refactor: schedule/hold API에서의 로깅 수정 및 동시성 테스트 추가

service/src/main/kotlin/com/sangdol/roomescape/schedule/business/ScheduleService.kt

@@ -71,10 +71,11 @@ class ScheduleService(
             id = id,
             currentStatus = ScheduleStatus.AVAILABLE,
             changeStatus = ScheduleStatus.HOLD
-        )
+        ).also {
+            log.info { "[ScheduleService.holdSchedule] $it 개의 row 변경 완료" }
+        }
 
         if (result == 0) {
-            log.info { "[ScheduleService.holdSchedule] Holding된 일정 없음: id=${id}, count = " }
             throw ScheduleException(ScheduleErrorCode.SCHEDULE_NOT_AVAILABLE)
         }
 

service/src/test/kotlin/com/sangdol/roomescape/schedule/ScheduleConcurrencyTest.kt

@@ -0,0 +1,59 @@
+package com.sangdol.roomescape.schedule
+
+import com.sangdol.common.types.web.HttpStatus
+import com.sangdol.roomescape.schedule.exception.ScheduleErrorCode
+import com.sangdol.roomescape.schedule.infrastructure.persistence.ScheduleRepository
+import com.sangdol.roomescape.schedule.infrastructure.persistence.ScheduleStatus
+import com.sangdol.roomescape.supports.FunSpecSpringbootTest
+import com.sangdol.roomescape.supports.runTest
+import io.kotest.assertions.assertSoftly
+import io.kotest.matchers.collections.shouldContainExactly
+import io.kotest.matchers.collections.shouldContainExactlyInAnyOrder
+import io.kotest.matchers.nulls.shouldNotBeNull
+import io.kotest.matchers.shouldBe
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.async
+import kotlinx.coroutines.awaitAll
+import kotlinx.coroutines.withContext
+import org.springframework.data.repository.findByIdOrNull
+import java.util.concurrent.CountDownLatch
+
+class ScheduleConcurrencyTest(
+    private val scheduleRepository: ScheduleRepository
+) : FunSpecSpringbootTest() {
+    init {
+        test("하나의 ${ScheduleStatus.AVAILABLE}인 일정에 대한 동시 HOLD 변경 요청이 들어오면, 가장 먼저 들어온 요청만 성공한다.") {
+            val user = testAuthUtil.defaultUserLogin()
+            val schedule = dummyInitializer.createSchedule()
+
+            withContext(Dispatchers.IO) {
+                val jobSize = 64
+                val latch = CountDownLatch(jobSize)
+
+                (1..jobSize).map {
+                    async {
+                        latch.countDown()
+                        latch.await()
+
+                        runTest(
+                            token = user.second,
+                            on = {
+                                post("/schedules/${schedule.id}/hold")
+                            },
+                            expect = {
+                            }
+                        ).extract().statusCode()
+                    }
+                }.awaitAll().also {
+                    it.count { statusCode -> statusCode == HttpStatus.OK.value() } shouldBe 1
+                    it.count { statusCode -> statusCode == ScheduleErrorCode.SCHEDULE_NOT_AVAILABLE.httpStatus.value() } shouldBe (jobSize - 1)
+                }
+            }
+
+            assertSoftly(scheduleRepository.findByIdOrNull(schedule.id)!!) {
+                this.status shouldBe ScheduleStatus.HOLD
+                this.holdExpiredAt.shouldNotBeNull()
+            }
+        }
+    }
+}