MC-39508: Spreading multiple GraphQL fragments into CategoryTree causes Magento to throw

Author: zakdma

app/code/Magento/CatalogGraphQl/Model/Category/DepthCalculator.php

@@ -7,6 +7,7 @@
 
 namespace Magento\CatalogGraphQl\Model\Category;
 
+use GraphQL\Language\AST\Node;
 use GraphQL\Language\AST\FieldNode;
 use GraphQL\Language\AST\InlineFragmentNode;
 use GraphQL\Language\AST\NodeKind;
@@ -26,22 +27,35 @@ class DepthCalculator
      */
     public function calculate(ResolveInfo $resolveInfo, FieldNode $fieldNode) : int
     {
-        $selections = $fieldNode->selectionSet->selections ?? [];
+        return $this->calculateRecursive($resolveInfo, $fieldNode);
+    }
+
+    /**
+     * Calculate recursive the total depth of a category tree inside a GraphQL request
+     *
+     * @param ResolveInfo $resolveInfo
+     * @param Node $node
+     * @return int
+     */
+    private function calculateRecursive(ResolveInfo $resolveInfo, Node $node) : int
+    {
+        if ($node->kind === NodeKind::FRAGMENT_SPREAD) {
+            $selections = isset($resolveInfo->fragments[$node->name->value]) ?
+                $resolveInfo->fragments[$node->name->value]->selectionSet->selections : [];
+        } else {
+            $selections = $node->selectionSet->selections ?? [];
+        }
         $depth = count($selections) ? 1 : 0;
         $childrenDepth = [0];
-        foreach ($selections as $node) {
-            if (isset($node->alias) && null !== $node->alias) {
+        foreach ($selections as $subNode) {
+            if (isset($subNode->alias) && null !== $subNode->alias) {
                 continue;
             }
 
-            if ($node->kind ===  NodeKind::INLINE_FRAGMENT) {
-                $childrenDepth[] = $this->addInlineFragmentDepth($resolveInfo, $node);
-            } elseif ($node->kind === NodeKind::FRAGMENT_SPREAD && isset($resolveInfo->fragments[$node->name->value])) {
-                foreach ($resolveInfo->fragments[$node->name->value]->selectionSet->selections as $spreadNode) {
-                    $childrenDepth[] = $this->calculate($resolveInfo, $spreadNode);
-                }
+            if ($subNode->kind ===  NodeKind::INLINE_FRAGMENT) {
+                $childrenDepth[] = $this->addInlineFragmentDepth($resolveInfo, $subNode);
             } else {
-                $childrenDepth[] = $this->calculate($resolveInfo, $node);
+                $childrenDepth[] = $this->calculateRecursive($resolveInfo, $subNode);
             }
         }
 

dev/tests/api-functional/testsuite/Magento/GraphQl/Catalog/CategoryListTest.php

@@ -842,4 +842,49 @@ public function testFilterCategoryNamedFragment()
         $this->assertEquals($result['categoryList'][0]['uid'], base64_encode('6'));
         $this->assertEquals($result['categoryList'][0]['url_path'], 'category-2');
     }
+
+    /**
+     * Test when there is recursive category node fragment
+     *
+     * @magentoApiDataFixture Magento/Catalog/_files/categories.php
+     */
+    public function testFilterCategoryRecursiveFragment() : void
+    {
+        $query = <<<'QUERY'
+query GetCategoryTree($filters: CategoryFilterInput!) {
+    categoryList(filters: $filters) {
+        ...recursiveCategoryNode
+    }
+}
+
+fragment recursiveCategoryNode on CategoryTree {
+  ...categoryNode
+  children {
+    ...categoryNode
+  }
+}
+
+fragment categoryNode on CategoryTree {
+  id
+}
+QUERY;
+        $variables = [
+            'filters' => [
+                'ids' => [
+                    'eq' => '2',
+                ],
+            ],
+        ];
+        $result = $this->graphQlQuery($query, $variables);
+        $this->assertArrayNotHasKey('errors', $result);
+        $this->assertCount(1, $result['categoryList']);
+        $this->assertCount(2, $result['categoryList'][0]);
+        $this->assertArrayHasKey('id', $result['categoryList'][0]);
+        $this->assertArrayHasKey('children', $result['categoryList'][0]);
+        $this->assertEquals($result['categoryList'][0]['id'], '2');
+        $this->assertCount(7, $result['categoryList'][0]['children']);
+        $this->assertCount(1, $result['categoryList'][0]['children'][0]);
+        $this->assertArrayHasKey('id', $result['categoryList'][0]['children'][0]);
+        $this->assertEquals($result['categoryList'][0]['children'][0]['id'], '3');
+    }
 }