MAGETWO-91568: Unable to retrieve filtered response to GET product custom attributes via REST API call

- Add custom filter for custom attributes

Author: YuliyaLabudova

dev/tests/api-functional/testsuite/Magento/Catalog/Api/ProductRepositoryInterfaceTest.php

@@ -802,6 +802,45 @@ public function testGetList()
         $this->assertEquals($expectedResult, $response['items'][0]['custom_attributes'][$index]['value']);
     }
 
+    /**
+     * @magentoApiDataFixture Magento/Catalog/_files/product_simple.php
+     */
+    public function testGetListWithAdditionalParams()
+    {
+        $this->_markTestAsRestOnly();
+        $searchCriteria = [
+            'searchCriteria' => [
+                'current_page' => 1,
+                'page_size' => 2,
+            ],
+        ];
+        $additionalParams = urlencode('items[id,custom_attributes[description]]');
+
+        $serviceInfo = [
+            'rest' => [
+                'resourcePath' => self::RESOURCE_PATH . '?' . http_build_query($searchCriteria) . '&fields=' .
+                    $additionalParams,
+                'httpMethod' => \Magento\Framework\Webapi\Rest\Request::HTTP_METHOD_GET,
+            ]
+        ];
+
+        $response = $this->_webApiCall($serviceInfo, $searchCriteria);
+
+        $this->assertArrayHasKey('items', $response);
+        $this->assertTrue(count($response['items']) > 0);
+
+        $indexDescription = null;
+        foreach ($response['items'][0]['custom_attributes'] as $key => $customAttribute) {
+            if ($customAttribute['attribute_code'] == 'description') {
+                $indexDescription = $key;
+            }
+        }
+
+        $this->assertNotNull($response['items'][0]['custom_attributes'][$indexDescription]['attribute_code']);
+        $this->assertNotNull($response['items'][0]['custom_attributes'][$indexDescription]['value']);
+        $this->assertTrue(count($response['items'][0]['custom_attributes']) == 1);
+    }
+
     /**
      * @magentoApiDataFixture Magento/Catalog/_files/products_with_websites_and_stores.php
      * @return void

lib/internal/Magento/Framework/Webapi/Rest/Response/FieldsFilter.php

@@ -6,6 +6,8 @@
 
 namespace Magento\Framework\Webapi\Rest\Response;
 
+use Magento\Framework\Api\AbstractExtensibleObject;
+use Magento\Framework\Api\AttributeInterface;
 use Magento\Framework\Webapi\Rest\Request as RestRequest;
 
 /**
@@ -178,10 +180,47 @@ protected function recursiveArrayIntersectKey(array $array1, array $array2)
         //If the field in array2 (filter) is not present in array1 (response) it will be removed after intersect
         $arrayIntersect = array_intersect_key($array1, $array2);
         foreach ($arrayIntersect as $key => &$value) {
+            if ($key == AbstractExtensibleObject::CUSTOM_ATTRIBUTES_KEY
+                && is_array($array2[AbstractExtensibleObject::CUSTOM_ATTRIBUTES_KEY])
+            ) {
+                $value = $this->filterCustomAttributes(
+                    $value,
+                    $array2[AbstractExtensibleObject::CUSTOM_ATTRIBUTES_KEY]
+                );
+                continue;
+            }
             if (is_array($value) && is_array($array2[$key])) {
                 $value = $this->applyFilter($value, $array2[$key]);
             }
         }
         return $arrayIntersect;
     }
+
+    /**
+     * Filter for custom attributes.
+     *
+     * @param array $item
+     * @param array $filter
+     * @return array
+     */
+    private function filterCustomAttributes(array $item, array $filter) : array
+    {
+        $fieldResult = [];
+        foreach ($item as $key => $field) {
+            $filterKeys = array_keys($filter);
+            if (in_array($field[AttributeInterface::ATTRIBUTE_CODE], $filterKeys)) {
+                $fieldResult[$key][AttributeInterface::ATTRIBUTE_CODE] = $field[AttributeInterface::ATTRIBUTE_CODE];
+                $fieldResult[$key][AttributeInterface::VALUE] = $field[AttributeInterface::VALUE];
+            } else {
+                if (isset($filter[AttributeInterface::ATTRIBUTE_CODE])) {
+                    $fieldResult[$key][AttributeInterface::ATTRIBUTE_CODE] = $field[AttributeInterface::ATTRIBUTE_CODE];
+                }
+                if (isset($filter[AttributeInterface::VALUE])) {
+                    $fieldResult[$key][AttributeInterface::VALUE] = $field[AttributeInterface::VALUE];
+                }
+            }
+        }
+
+        return $fieldResult;
+    }
 }