[Bug]: Cannot use concatenator on attributes in object bricks because of null value exception. (#569)

* Fix: Error when concatenate empty values

* Apply php-cs-fixer changes

Co-authored-by: robertSt7 <[email protected]>

Author: robertSt7

src/GraphQL/Query/Operator/Concatenator.php

@@ -47,6 +47,9 @@ public function getLabeledValue($element, ResolveInfo $resolveInfo = null)
             $valueResolver = $this->getGraphQlService()->buildValueResolverFromAttributes($c);
 
             $childResult = $valueResolver->getLabeledValue($element, $resolveInfo);
+            if ($childResult == null) {
+                continue;
+            }
             $childValues = $childResult->value;
             if ($childValues && !is_array($childValues)) {
                 $childValues = [$childValues];