fix(product, utils): handle metadata key deletion on product update (#12478)

packages/modules/product/src/repositories/product.ts

@@ -6,6 +6,8 @@ import {
   buildQuery,
   DALUtils,
   MedusaError,
+  isPresent,
+  mergeMetadata,
 } from "@medusajs/framework/utils"
 import { SqlEntityManager, wrap } from "@mikro-orm/postgresql"
 
@@ -148,6 +150,10 @@ export class ProductRepository extends DALUtils.mikroOrmBaseRepositoryFactory(
         )
       }
 
+      if (isPresent(productToUpdate.metadata)) {
+        productToUpdate.metadata = mergeMetadata(product.metadata ?? {}, productToUpdate.metadata)
+      }
+
       wrappedProduct.assign(productToUpdate)
     }