From 07f10c83606e71ff59f94884a8d1402d17ff8efd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Ad=C3=A1mek?= <banan23@gmail.com>
Date: Thu, 2 May 2024 21:09:06 +0200
Subject: [PATCH] fix(core): fix hydration of relations with custom types via
 joined strategy

This was resulting in an additional query used by the fallback select-in mechanism, so it wasn't surfacing that obviously.

Closes #5518
---
 packages/core/src/hydration/ObjectHydrator.ts |  2 +-
 packages/core/src/types/UuidType.ts           |  4 ++
 tests/issues/GH5518.test.ts                   | 72 +++++++++++++++++++
 3 files changed, 77 insertions(+), 1 deletion(-)
 create mode 100644 tests/issues/GH5518.test.ts

diff --git a/packages/core/src/hydration/ObjectHydrator.ts b/packages/core/src/hydration/ObjectHydrator.ts
index 75a239c828c5..3cb45dbff0ce 100644
--- a/packages/core/src/hydration/ObjectHydrator.ts
+++ b/packages/core/src/hydration/ObjectHydrator.ts
@@ -174,7 +174,7 @@ export class ObjectHydrator extends Hydrator {
       if (prop.customType?.ensureComparable(meta, prop)) {
         context.set(`convertToDatabaseValue_${this.safeKey(prop.name)}`, (val: any) => prop.customType!.convertToDatabaseValue(val, this.platform, { mode: 'hydration' }));
 
-        ret.push(`  if (data${dataKey} != null && convertCustomTypes) {`);
+        ret.push(`  if (data${dataKey} != null && typeof data${dataKey} !== 'object' && convertCustomTypes) {`);
         ret.push(`    data${dataKey} = convertToDatabaseValue_${this.safeKey(prop.name)}(entity${entityKey}.__helper.getPrimaryKey());`);
         ret.push(`  }`);
       }
diff --git a/packages/core/src/types/UuidType.ts b/packages/core/src/types/UuidType.ts
index 84e83b5bdb3b..af372d490b75 100644
--- a/packages/core/src/types/UuidType.ts
+++ b/packages/core/src/types/UuidType.ts
@@ -12,4 +12,8 @@ export class UuidType extends Type<string | null | undefined> {
     return 'string';
   }
 
+  override ensureComparable(): boolean {
+    return false;
+  }
+
 }
diff --git a/tests/issues/GH5518.test.ts b/tests/issues/GH5518.test.ts
new file mode 100644
index 000000000000..777e2f0932a3
--- /dev/null
+++ b/tests/issues/GH5518.test.ts
@@ -0,0 +1,72 @@
+import { Collection, Entity, ManyToOne, MikroORM, OneToMany, PrimaryKey, Property, Ref, types } from '@mikro-orm/sqlite';
+import { mockLogger } from '../helpers';
+
+abstract class BaseEntity {
+
+  @PrimaryKey({
+    type: types.uuid,
+    onCreate: () => crypto.randomUUID(),
+  })
+  id!: string;
+
+}
+
+@Entity()
+class Product extends BaseEntity {
+
+  @Property()
+  name!: string;
+
+  @Property()
+  price!: number;
+
+}
+
+@Entity()
+class Order extends BaseEntity {
+
+  @OneToMany(() => OrderItem, e => e.order)
+  items!: Collection<OrderItem>;
+
+}
+
+
+@Entity()
+class OrderItem {
+
+  @ManyToOne(() => Order, { primary: true, ref: true })
+  order!: Ref<Order>;
+
+  @ManyToOne(() => Product, { primary: true, ref: true })
+  product!: Ref<Product>;
+
+}
+
+let orm: MikroORM;
+
+beforeAll(async () => {
+  orm = await MikroORM.init({
+    dbName: ':memory:',
+    entities: [Product, Order, OrderItem],
+  });
+  await orm.schema.refreshDatabase();
+});
+
+afterAll(async () => {
+  await orm.close(true);
+});
+
+test('basic CRUD example', async () => {
+  const product = orm.em.create(Product, { name: 'Product 1', price: 100 });
+  const order = orm.em.create(Order, {});
+  order.items.add(orm.em.create(OrderItem, { order, product }));
+  await orm.em.flush();
+  orm.em.clear();
+
+  const mock = mockLogger(orm);
+  const [item] = await orm.em.find(OrderItem, { order: order.id }, {
+    populate: ['product'],
+  });
+  expect(item.product.isInitialized()).toBe(true);
+  expect(mock).toHaveBeenCalledTimes(1);
+});