fix: mongodb resolves leaked cursor (#10316)

FxEasy · web-flow · commit 2dc9624d0016 · 2023-12-29T20:20:49.000+05:00
This change resolves a leaked cursor used to avoid a stack overflow during entity transformation. Closes: #10315
diff --git a/src/entity-manager/MongoEntityManager.ts b/src/entity-manager/MongoEntityManager.ts
@@ -1025,11 +1025,11 @@ export class MongoEntityManager extends EntityManager {
         cursor: FindCursor<Entity> | AggregationCursor<Entity>,
     ) {
         const queryRunner = this.mongoQueryRunner
-        cursor.toArray = () =>
-            cursor
-                .clone()
-                .toArray()
-                .then(async (results: Entity[]) => {
+
+        ;(cursor as any)["__to_array_func"] = cursor.toArray
+        cursor.toArray = async () =>
+            ((cursor as any)["__to_array_func"] as CallableFunction)().then(
+                async (results: Entity[]) => {
                     const transformer = new DocumentToEntityTransformer()
                     const entities = transformer.transformAll(results, metadata)
                     // broadcast "load" events
@@ -1039,13 +1039,12 @@ export class MongoEntityManager extends EntityManager {
                         entities,
                     )
                     return entities
-                })
-
-        cursor.next = () =>
-            cursor
-                .clone()
-                .next()
-                .then(async (result: Entity) => {
+                },
+            )
+        ;(cursor as any)["__next_func"] = cursor.next
+        cursor.next = async () =>
+            ((cursor as any)["__next_func"] as CallableFunction)().then(
+                async (result: Entity) => {
                     if (!result) {
                         return result
                     }
@@ -1056,7 +1055,8 @@ export class MongoEntityManager extends EntityManager {
                         entity,
                     ])
                     return entity
-                })
+                },
+            )
     }
 
     protected filterSoftDeleted<Entity>(
