FEATURE: Log query exceptions

The GraphQL library I use (webonyx/graphql-php) conveniently
converts any exceptions into a GraphQL "error result".
This leads to the exception handler not being triggered any longer.

With this change any exception that occurs during processing of a GraphQL
query is logged using the Flow `SystemLogger`.

Classes/View/GraphQlView.php

@@ -5,12 +5,19 @@
 use GraphQL\Executor\ExecutionResult;
 use TYPO3\Flow\Annotations as Flow;
 use TYPO3\Flow\Http\Response as HttpResponse;
+use TYPO3\Flow\Log\SystemLoggerInterface;
 use TYPO3\Flow\Mvc\View\AbstractView;
 use TYPO3\Flow\Exception as FlowException;
 
 class GraphQlView extends AbstractView
 {
 
+    /**
+     * @Flow\Inject
+     * @var SystemLoggerInterface
+     */
+    protected $systemLogger;
+
     /**
      * @return string The rendered view
      * @throws FlowException
@@ -57,6 +64,9 @@ private function formatResult(ExecutionResult $executionResult)
                     $errorResult['_statusCode'] = $exception->getStatusCode();
                     $errorResult['_referenceCode'] = $exception->getReferenceCode();
                 }
+                if ($exception instanceof \Exception) {
+                    $this->systemLogger->logException($exception);
+                }
                 return $errorResult;
             }, $executionResult->errors);
         }