From 67fd88a08310daeb1bd60c73fcd5b0823c4db011 Mon Sep 17 00:00:00 2001
From: TaprootFreak <142087526+TaprootFreak@users.noreply.github.com>
Date: Fri, 22 May 2026 11:36:33 +0200
Subject: [PATCH] fix: circular JSON in buyCrypto update response

BuyCryptoController.update and manualPassAmlCheck returned the raw
BuyCrypto entity loaded with transaction.userData.kycSteps. TypeORM
populates the KycStep.userData inverse back-reference, producing a
circular object graph that JSON.stringify rejects -> 500 on
PUT /v1/buyCrypto/:id.

The kycSteps relation is required by the update logic, so reload the
entity without the cyclic userData collections for the response.
---
 .../process/services/buy-crypto.service.ts       | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/subdomains/core/buy-crypto/process/services/buy-crypto.service.ts b/src/subdomains/core/buy-crypto/process/services/buy-crypto.service.ts
index 2fb3307965..4f9a46900b 100644
--- a/src/subdomains/core/buy-crypto/process/services/buy-crypto.service.ts
+++ b/src/subdomains/core/buy-crypto/process/services/buy-crypto.service.ts
@@ -414,7 +414,21 @@ export class BuyCryptoService implements OnModuleInit {
       await this.updateCryptoRouteVolume([cryptoRouteIdBefore, entity.cryptoRoute?.id]);
     if (dto.usedRef || dto.amountInEur) await this.updateRefVolume([usedRefBefore, entity.usedRef]);
 
-    return entity;
+    // reload without userData.kycSteps/users: TypeORM sets the inverse back-reference on those
+    // collections, producing a circular graph that breaks JSON serialization of the response
+    return this.buyCryptoRepo.findOne({
+      where: { id },
+      relations: {
+        buy: true,
+        cryptoRoute: true,
+        cryptoInput: true,
+        bankTx: true,
+        checkoutTx: true,
+        transaction: { user: { wallet: true }, userData: true },
+        chargebackOutput: true,
+        bankData: true,
+      },
+    });
   }
 
   private async changeRoute(entity: BuyCrypto, route: Buy | Swap) {