[ApiBundle] Fix 404 on GET /shop/products/{code} when all associated products are disabled (#19018)

| Q               | A
|-----------------|-----
| Branch?         | 2.2
| Bug fix?        | yes
| New feature?    | no
| BC breaks?      | no
| Deprecations?   | no
| Related tickets | https://github.com/Sylius/Sylius/issues/19013
| License         | MIT

  ### Summary

`GET /api/v2/shop/products/{code}` returned **404** for an `enabled`
product whenever
*all* of its associated products (across all its associations) were
disabled.

  Root cause: `EnabledWithinProductAssociationExtension` applied
`andWhere('product.associations IS EMPTY OR associatedProduct.id IS NOT
NULL')`
both in `applyToCollection` and `applyToItem`. For an item query, the OR
collapsed
to `false` whenever the product had associations but none of their
associated
  products were enabled — excluding the product itself from the result.

  ### Fix

Removed the `andWhere` from the extension. Eager-loading of enabled
associated
products (`LEFT JOIN ... WITH associatedProduct.enabled = true`) stays
in place
and mirrors the convention used by the neighbouring
`EnabledVariantsExtension`.

src/Sylius/Bundle/ApiBundle/Doctrine/ORM/QueryExtension/Shop/Product/EnabledWithinProductAssociationExtension.php

@@ -86,7 +86,6 @@ final readonly class EnabledWithinProductAssociationExtension implements QueryCo
                     $queryBuilder->expr()->eq(sprintf('%s.owner', $associationAliasName), $rootAlias),
                 ),
             )
-            ->andWhere(sprintf('%s.associations IS EMPTY OR %s.id IS NOT NULL', $rootAlias, $productAssociationAliasName))
         ;
     }
 }

src/Sylius/Bundle/ApiBundle/tests/Doctrine/ORM/QueryExtension/Shop/Product/EnabledWithinProductAssociationExtensionTest.php

@@ -82,7 +82,7 @@ final class EnabledWithinProductAssociationExtensionTest extends TestCase
         );
     }
 
-    public function test_it_filters_products_by_available_associations(): void
+    public function test_it_eager_loads_only_enabled_associated_products(): void
     {
         $this->sectionProvider->method('getSection')->willReturn(new ShopApiSection());
 
@@ -147,10 +147,8 @@ final class EnabledWithinProductAssociationExtensionTest extends TestCase
             });
 
         $this->queryBuilder
-            ->expects(self::once())
-            ->method('andWhere')
-            ->with('o.associations IS EMPTY OR associatedProduct.id IS NOT NULL')
-            ->willReturnSelf();
+            ->expects(self::never())
+            ->method('andWhere');
 
         $this->extension->applyToCollection(
             $this->queryBuilder,

tests/Api/DataFixtures/ORM/product/product_with_only_disabled_associated_products.yaml

@@ -0,0 +1,63 @@
+Sylius\Component\Core\Model\Channel:
+    channel_web:
+        code: 'WEB'
+        name: 'Web Channel'
+        hostname: 'localhost'
+        description: 'Lorem ipsum'
+        baseCurrency: '@currency_usd'
+        defaultLocale: '@locale_en'
+        locales: ['@locale_en']
+        color: 'black'
+        enabled: true
+        taxCalculationStrategy: 'order_items_based'
+
+Sylius\Component\Currency\Model\Currency:
+    currency_usd:
+        code: 'USD'
+
+Sylius\Component\Locale\Model\Locale:
+    locale_en:
+        code: 'en_US'
+
+Sylius\Component\Core\Model\Product:
+    product_kettle:
+        code: 'KETTLE'
+        channels: ['@channel_web']
+        currentLocale: 'en_US'
+    product_disabled_hat:
+        code: 'DISABLED_HAT'
+        channels: ['@channel_web']
+        currentLocale: 'en_US'
+        enabled: false
+
+Sylius\Component\Core\Model\ProductTranslation:
+    product_translation_kettle_en_US:
+        slug: 'kettle'
+        locale: 'en_US'
+        name: 'Kettle'
+        description: 'A nice kettle'
+        shortDescription: 'Kettle'
+        translatable: '@product_kettle'
+    product_translation_disabled_hat_en_US:
+        slug: 'disabled-hat'
+        locale: 'en_US'
+        name: 'Disabled Hat'
+        description: 'A hat that is not enabled'
+        shortDescription: 'Disabled Hat'
+        translatable: '@product_disabled_hat'
+
+Sylius\Component\Product\Model\ProductAssociationType:
+    similar_products_type:
+        code: 'similar_products'
+
+Sylius\Component\Product\Model\ProductAssociationTypeTranslation:
+    similar_products_type_translation_en_US:
+        name: 'Similar products'
+        locale: 'en_US'
+        translatable: '@similar_products_type'
+
+Sylius\Component\Product\Model\ProductAssociation:
+    kettle_dead_association:
+        type: '@similar_products_type'
+        owner: '@product_kettle'
+        associatedProducts: ['@product_disabled_hat']

tests/Api/Shop/ProductsTest.php

@@ -154,6 +154,20 @@ final class ProductsTest extends JsonApiTestCase
         );
     }
 
+    #[Test]
+    public function it_returns_enabled_product_item_when_all_its_associated_products_are_disabled(): void
+    {
+        $this->loadFixturesFromFile('product/product_with_only_disabled_associated_products.yaml');
+
+        $this->client->request(
+            method: 'GET',
+            uri: '/api/v2/shop/products/KETTLE',
+            server: self::CONTENT_TYPE_HEADER,
+        );
+
+        $this->assertResponseCode($this->client->getResponse(), Response::HTTP_OK);
+    }
+
     #[Test]
     public function it_returns_associated_products_collection_by_association_type(): void
     {