From e8fdb20b98b88ec330ef41ee5b7454e68bad5f25 Mon Sep 17 00:00:00 2001
From: Nassim Tabchiche <n.tabchiche2@gmail.com>
Date: Thu, 12 Dec 2024 15:36:43 +0100
Subject: [PATCH] Check that parent assets do not cause a cycle in the assets
 graph

---
 backend/core/serializers.py | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/backend/core/serializers.py b/backend/core/serializers.py
index 0e3c95ae7..c741ef570 100644
--- a/backend/core/serializers.py
+++ b/backend/core/serializers.py
@@ -220,6 +220,20 @@ class Meta:
         model = Asset
         fields = "__all__"
 
+    def validate_parent_assets(self, parent_assets):
+        """
+        Check that the assets graph will not contain cycles
+        """
+        if not self.instance:
+            return parent_assets
+        if parent_assets:
+            for asset in parent_assets:
+                if self.instance in asset.ancestors_plus_self():
+                    raise serializers.ValidationError(
+                        "errorAssetGraphMustNotContainCycles"
+                    )
+        return parent_assets
+
 
 class AssetReadSerializer(AssetWriteSerializer):
     folder = FieldsRelatedField()