fix: Remove extra saving on serialization which breaks the chain (#9465)

**What**
The extra serialization check hapen to break the serialization chain by reusing already serialized entities when they have been serialized from a different parents sequence

packages/core/utils/src/dal/mikro-orm/__fixtures__/utils.ts

@@ -1,6 +1,8 @@
 import {
+  Cascade,
   Collection,
   Entity,
+  ManyToMany,
   ManyToOne,
   OneToMany,
   PrimaryKey,
@@ -9,6 +11,104 @@ import {
 } from "@mikro-orm/core"
 import { Searchable } from "../decorators/searchable"
 
+@Entity()
+class Product {
+  @PrimaryKey()
+  id: string
+
+  @Property()
+  name: string
+
+  @OneToMany(() => ProductOption, (o) => o.product, {
+    cascade: ["soft-remove"] as any,
+  })
+  options = new Collection<ProductOption>(this)
+
+  @OneToMany(() => ProductVariant, (variant) => variant.product, {
+    cascade: ["soft-remove"] as any,
+  })
+  variants = new Collection<ProductVariant>(this)
+}
+
+@Entity()
+class ProductOption {
+  @PrimaryKey()
+  id: string
+
+  @Property()
+  name: string
+
+  @ManyToOne(() => Product, {
+    persist: false,
+    nullable: true,
+  })
+  product: Product | null
+
+  @OneToMany(() => ProductOptionValue, (value) => value.option, {
+    cascade: [Cascade.PERSIST, "soft-remove" as any],
+  })
+  values = new Collection<ProductOptionValue>(this)
+}
+
+@Entity()
+class ProductOptionValue {
+  @PrimaryKey()
+  id: string
+
+  @Property()
+  name: string
+
+  @ManyToOne(() => ProductOption, {
+    columnType: "text",
+    fieldName: "option_id",
+    mapToPk: true,
+    nullable: true,
+    onDelete: "cascade",
+  })
+  option_id: string | null
+
+  @ManyToOne(() => ProductOption, {
+    nullable: true,
+    persist: false,
+  })
+  option: ProductOption | null
+
+  @ManyToMany(() => ProductVariant, (variant) => variant.options)
+  variants = new Collection<ProductVariant>(this)
+}
+
+@Entity()
+class ProductVariant {
+  @PrimaryKey()
+  id: string
+
+  @Property()
+  name: string
+
+  @ManyToOne(() => Product, {
+    columnType: "text",
+    nullable: true,
+    onDelete: "cascade",
+    fieldName: "product_id",
+    mapToPk: true,
+  })
+  product_id: string | null
+
+  @ManyToOne(() => Product, {
+    persist: false,
+    nullable: true,
+  })
+  product: Product | null
+
+  @ManyToMany(() => ProductOptionValue, "variants", {
+    owner: true,
+    pivotTable: "product_variant_option",
+    joinColumn: "variant_id",
+    inverseJoinColumn: "option_value_id",
+  })
+  options = new Collection<ProductOptionValue>(this)
+}
+
 // Circular dependency one level
 @Entity()
 class RecursiveEntity1 {
@@ -114,6 +214,11 @@ class DeepRecursiveEntity1 {
   @Property({ nullable: true })
   deleted_at: Date | null
 
+  @OneToMany(() => DeepRecursiveEntity3, (entity3) => entity3.entity1, {
+    cascade: ["soft-remove"] as any,
+  })
+  entity3 = new Collection<DeepRecursiveEntity3>(this)
+
   @OneToMany(() => DeepRecursiveEntity2, (entity2) => entity2.entity1, {
     cascade: ["soft-remove"] as any,
   })
@@ -349,4 +454,8 @@ export {
   RecursiveEntity2,
   SearchableEntity1,
   SearchableEntity2,
+  Product,
+  ProductOption,
+  ProductOptionValue,
+  ProductVariant,
 }

packages/core/utils/src/dal/mikro-orm/__tests__/mikro-orm-serializer.spec.ts

@@ -2,13 +2,24 @@ import { MikroORM } from "@mikro-orm/core"
 import {
   Entity1WithUnDecoratedProp,
   Entity2WithUnDecoratedProp,
+  Product,
+  ProductOption,
+  ProductOptionValue,
+  ProductVariant,
 } from "../__fixtures__/utils"
 import { mikroOrmSerializer } from "../mikro-orm-serializer"
 
 describe("mikroOrmSerializer", () => {
   beforeEach(async () => {
     await MikroORM.init({
-      entities: [Entity1WithUnDecoratedProp, Entity2WithUnDecoratedProp],
+      entities: [
+        Entity1WithUnDecoratedProp,
+        Entity2WithUnDecoratedProp,
+        Product,
+        ProductOption,
+        ProductOptionValue,
+        ProductVariant,
+      ],
       dbName: "test",
       type: "postgresql",
     })
@@ -119,4 +130,70 @@ describe("mikroOrmSerializer", () => {
       ],
     })
   })
+
+  it(`should properly serialize nested relations and sibling to not return parents into children`, async () => {
+    const productOptionValue = new ProductOptionValue()
+    productOptionValue.id = "1"
+    productOptionValue.name = "Product option value 1"
+    productOptionValue.option_id = "1"
+
+    const productOptions = new ProductOption()
+    productOptions.id = "1"
+    productOptions.name = "Product option 1"
+    productOptions.values.add(productOptionValue)
+
+    const productVariant = new ProductVariant()
+    productVariant.id = "1"
+    productVariant.name = "Product variant 1"
+    productVariant.options.add(productOptionValue)
+
+    const product = new Product()
+    product.id = "1"
+    product.name = "Product 1"
+    product.options.add(productOptions)
+    product.variants.add(productVariant)
+
+    const serialized = await mikroOrmSerializer(product)
+
+    expect(serialized).toEqual({
+      id: "1",
+      options: [
+        {
+          id: "1",
+          values: [
+            {
+              id: "1",
+              variants: [
+                {
+                  id: "1",
+                  name: "Product variant 1",
+                },
+              ],
+              name: "Product option value 1",
+              option_id: "1",
+            },
+          ],
+          name: "Product option 1",
+        },
+      ],
+      variants: [
+        {
+          id: "1",
+          options: [
+            {
+              id: "1",
+              name: "Product option value 1",
+              option_id: "1",
+              option: {
+                id: "1",
+                name: "Product option 1",
+              },
+            },
+          ],
+          name: "Product variant 1",
+        },
+      ],
+      name: "Product 1",
+    })
+  })
 })

packages/core/utils/src/dal/mikro-orm/mikro-orm-serializer.ts

@@ -142,16 +142,6 @@ export class EntitySerializer {
       root.visited.add(entity)
     }
 
-    // Virtually augment the serialization context
-    root.visitedSerialized ??= new Map()
-    const primaryKeysValues = Array.from(keys)
-      .map((key) => entity[key])
-      .join("-")
-
-    if (root.visitedSerialized.has(primaryKeysValues)) {
-      return root.visitedSerialized.get(primaryKeysValues)
-    }
-
     ;[...keys]
       /** Medusa Custom properties filtering **/
       .filter((prop) =>
@@ -242,7 +232,7 @@ export class EntitySerializer {
               parents_
             ))
       )
-    root.visitedSerialized.set(primaryKeysValues, ret)
+
     return ret
   }