MC-33288: [2.4][MSI][MFTF] StorefrontLoggedInCustomerCreateOrderAllOptionQuantityConfigurableProductCustomStockTest fails because of bad design

Author: mastiuhin-olexandr

app/code/Magento/Catalog/Model/ResourceModel/Product/Relation.php

@@ -148,12 +148,12 @@ public function getRelationsByChildren(array $childrenIds): array
         $select = $connection->select()
             ->from(
                 ['cpe' => $this->getTable('catalog_product_entity')],
-                'entity_id'
+                ['relation.child_id', 'cpe.entity_id']
             )->join(
                 ['relation' => $this->getTable('catalog_product_relation')],
                 'relation.parent_id = cpe.' . $linkField
             )->where('relation.child_id IN(?)', $childrenIds);
 
-        return $connection->fetchCol($select);
+        return $connection->fetchPairs($select);
     }
 }

dev/tests/integration/testsuite/Magento/ConfigurableProduct/Model/ResourceModel/Product/RelationTest.php

@@ -57,30 +57,53 @@ protected function setUp(): void
      */
     public function testGetRelationsByChildren(): void
     {
-        // Find configurable products options
-        $productOptionSkus = ['simple_10', 'simple_20', 'simple_30', 'simple_40'];
-        $searchCriteria = $this->searchCriteriaBuilder->addFilter('sku', $productOptionSkus, 'in')
+        $childSkusOfParentSkus = [
+            'configurable' => ['simple_10', 'simple_20'],
+            'configurable_12345' => ['simple_30', 'simple_40'],
+        ];
+        $configurableSkus = [
+            'configurable',
+            'configurable_12345',
+            'simple_10',
+            'simple_20',
+            'simple_30',
+            'simple_40',
+        ];
+        $configurableIdsOfSkus = [];
+
+        $searchCriteria = $this->searchCriteriaBuilder->addFilter('sku', $configurableSkus, 'in')
             ->create();
-        $productOptions = $this->productRepository->getList($searchCriteria)
+        $configurableProducts = $this->productRepository->getList($searchCriteria)
             ->getItems();
 
-        $productOptionsIds = [];
+        $childIds = [];
 
-        foreach ($productOptions as $productOption) {
-            $productOptionsIds[] = $productOption->getId();
+        foreach ($configurableProducts as $product) {
+            $configurableIdsOfSkus[$product->getSku()] = $product->getId();
+
+            if ($product->getTypeId() != 'configurable') {
+                $childIds[] = $product->getId();
+            }
         }
 
-        // Find configurable products
-        $searchCriteria = $this->searchCriteriaBuilder->addFilter('sku', ['configurable', 'configurable_12345'], 'in')
-            ->create();
-        $configurableProducts = $this->productRepository->getList($searchCriteria)
-            ->getItems();
+        $parentIdsOfChildIds = [];
+
+        foreach ($childSkusOfParentSkus as $parentSku => $childSkus) {
+            foreach ($childSkus as $childSku) {
+                $childId = $configurableIdsOfSkus[$childSku];
+                $parentIdsOfChildIds[$childId][] = $configurableIdsOfSkus[$parentSku];
+            }
+        }
 
-        // Assert there are configurable products ids in result of getRelationsByChildren method.
-        $result = $this->model->getRelationsByChildren($productOptionsIds);
+        /**
+         * Assert there are parent configurable products ids in result of getRelationsByChildren method
+         * and they are related to child ids.
+         */
+        $result = $this->model->getRelationsByChildren($childIds);
 
-        foreach ($configurableProducts as $configurableProduct) {
-            $this->assertContains($configurableProduct->getId(), $result);
+        foreach ($childIds as $childId) {
+            $this->assertArrayHasKey($childId, $result);
+            $this->assertContains($result[$childId], $parentIdsOfChildIds[$childId]);
         }
     }
 }