전체 코드, 구조 검토 - P0 코드 수정 진행

lib/upgrade-requests.ts

@@ -121,48 +121,69 @@ export async function approveUpgradeRequest(
   requestedAccountType: number;
 }> {
   return db.$transaction(async (tx) => {
-    const request = await getActionTarget(tx, maestroUpgradeID);
+    // Atomically claim the request — prevents concurrent double-approval
+    const claimed = await tx.maestro_upgrade.updateMany({
+      where: { MaestroUpgradeID: maestroUpgradeID, Status: REQUEST_STATUSES.REQUESTED },
+      data: { Status: REQUEST_STATUSES.APPLIED },
+    });
+    if (claimed.count === 0) {
+      const exists = await tx.maestro_upgrade.count({
+        where: { MaestroUpgradeID: maestroUpgradeID },
+      });
+      throw new ApiError(
+        exists ? "이미 처리된 업그레이드 신청입니다." : "업그레이드 신청을 찾을 수 없습니다.",
+        exists ? 409 : 404
+      );
+    }
+
+    const request = await tx.maestro_upgrade.findUnique({
+      where: { MaestroUpgradeID: maestroUpgradeID },
+      select: {
+        MaestroID: true,
+        RequestedAccountType: true,
+        RegisteredActivateStatus: true,
+        RegisteredAccountType: true,
+        maestro: { select: { Name: true, Email: true } },
+      },
+    });
+
     const availableActivateDateTime = calculateUpgradeAvailableDate();
 
     await tx.maestro.update({
-      where: { MaestroID: request.MaestroID },
+      where: { MaestroID: request!.MaestroID },
       data: {
-        AccountType: request.RequestedAccountType,
+        AccountType: request!.RequestedAccountType,
         ActivateStatus: ACTIVATE_STATUSES.ACTIVE,
         AvailableActivateDateTime: availableActivateDateTime,
       },
     });
     await tx.maestro_upgrade.updateMany({
       where: {
-        MaestroID: request.MaestroID,
+        MaestroID: request!.MaestroID,
         Status: REQUEST_STATUSES.REQUESTED,
       },
       data: { Status: REQUEST_STATUSES.CLOSED },
     });
-    await tx.maestro_upgrade.update({
-      where: { MaestroUpgradeID: request.MaestroUpgradeID },
-      data: { Status: REQUEST_STATUSES.APPLIED },
-    });
     await tx.maestro_log.create({
       data: {
         Type: "upgrade_maestro",
-        MaestroID: request.MaestroID,
+        MaestroID: request!.MaestroID,
         LogDateTime: new Date(),
         Remark: buildUpgradeLogRemark(
-          request.RegisteredActivateStatus,
-          request.RegisteredAccountType,
-          request.RequestedAccountType
+          request!.RegisteredActivateStatus,
+          request!.RegisteredAccountType,
+          request!.RequestedAccountType
         ),
       },
     });
 
     return {
       availableActivateDateTime: availableActivateDateTime.toISOString(),
-      maestroName: request.maestro.Name.trim(),
-      maestroEmail: request.maestro.Email.trim(),
-      registeredActivateStatus: request.RegisteredActivateStatus,
-      registeredAccountType: request.RegisteredAccountType,
-      requestedAccountType: request.RequestedAccountType,
+      maestroName: request!.maestro.Name.trim(),
+      maestroEmail: request!.maestro.Email.trim(),
+      registeredActivateStatus: request!.RegisteredActivateStatus,
+      registeredAccountType: request!.RegisteredAccountType,
+      requestedAccountType: request!.RequestedAccountType,
     };
   });
 }
@@ -215,21 +236,39 @@ export async function rejectUpgradeRequest(
   maestroUpgradeID: number
 ): Promise<void> {
   await db.$transaction(async (tx) => {
-    const request = await getActionTarget(tx, maestroUpgradeID);
-
-    await tx.maestro_upgrade.update({
-      where: { MaestroUpgradeID: request.MaestroUpgradeID },
+    const claimed = await tx.maestro_upgrade.updateMany({
+      where: { MaestroUpgradeID: maestroUpgradeID, Status: REQUEST_STATUSES.REQUESTED },
       data: { Status: REQUEST_STATUSES.CLOSED },
     });
+    if (claimed.count === 0) {
+      const exists = await tx.maestro_upgrade.count({
+        where: { MaestroUpgradeID: maestroUpgradeID },
+      });
+      throw new ApiError(
+        exists ? "이미 처리된 업그레이드 신청입니다." : "업그레이드 신청을 찾을 수 없습니다.",
+        exists ? 409 : 404
+      );
+    }
+
+    const request = await tx.maestro_upgrade.findUnique({
+      where: { MaestroUpgradeID: maestroUpgradeID },
+      select: {
+        MaestroID: true,
+        RegisteredActivateStatus: true,
+        RegisteredAccountType: true,
+        RequestedAccountType: true,
+      },
+    });
+
     await tx.maestro_log.create({
       data: {
         Type: "reject_upgrade_maestro",
-        MaestroID: request.MaestroID,
+        MaestroID: request!.MaestroID,
         LogDateTime: new Date(),
         Remark: buildUpgradeLogRemark(
-          request.RegisteredActivateStatus,
-          request.RegisteredAccountType,
-          request.RequestedAccountType
+          request!.RegisteredActivateStatus,
+          request!.RegisteredAccountType,
+          request!.RequestedAccountType
         ),
       },
     });
@@ -244,31 +283,6 @@ export function parseUpgradeRequestSearchParams(
   );
 }
 
-async function getActionTarget(
-  tx: Prisma.TransactionClient,
-  maestroUpgradeID: number
-) {
-  const request = await tx.maestro_upgrade.findUnique({
-    where: { MaestroUpgradeID: maestroUpgradeID },
-    include: { maestro: { select: { Name: true, Email: true } } },
-  });
-
-  if (!request) {
-    throw new ApiError(
-      "업그레이드 신청을 찾을 수 없습니다.",
-      404
-    );
-  }
-
-  if (request.Status !== REQUEST_STATUSES.REQUESTED) {
-    throw new ApiError(
-      "이미 처리된 업그레이드 신청입니다.",
-      409
-    );
-  }
-
-  return request;
-}
 
 function buildUpgradeRequestWhere(
   params: UpgradeRequestSearchParams