B2B-2658: Implement GraphQL Resolver Cache for Customer query

- added array checks for values before processing

Author: rganin

app/code/Magento/GraphQlResolverCache/Model/Plugin/Resolver/Cache.php

@@ -166,7 +166,9 @@ private function executeResolver(
         array &$value = null,
         array $args = null
     ) {
-        $this->valueProcessor->preProcessParentValue($value);
+        if (is_array($value)) {
+            $this->valueProcessor->preProcessParentValue($value);
+        }
         return $closure($field, $context, $info, $value, $args);
     }
 

app/code/Magento/GraphQlResolverCache/Model/Resolver/Result/CacheKey/Calculator.php

@@ -88,8 +88,10 @@ public function calculateCacheKey(?array $parentResolverData = null): ?string
             foreach ($this->factorProviderInstances as $provider) {
                 if ($provider instanceof ParentValueFactorProviderInterface) {
                     // trigger data hydration for key calculation
-                    // only when the parent-dependent key factor provider is called
-                    $this->valueProcessor->preProcessParentValue($parentResolverData);
+                    // only when the parent-dependent key factor provider is called and the value is an array
+                    if (is_array($parentResolverData)) {
+                        $this->valueProcessor->preProcessParentValue($parentResolverData);
+                    }
                     $keys[$provider->getFactorName()] = $provider->getFactorValue(
                         $context,
                         $parentResolverData