fix: fix edge cases with $ref

Author: DannyvdSluijs

src/JsonSchema/SchemaStorage.php

@@ -147,6 +147,7 @@ public function resolveRef(string $ref, $resolveStack = [])
         // get & process the schema
         $refSchema = $this->getSchema($fileName);
         foreach ($jsonPointer->getPropertyPaths() as $path) {
+            $path = urldecode($path);
             if (is_object($refSchema) && property_exists($refSchema, $path)) {
                 $refSchema = $this->resolveRefSchema($refSchema->{$path}, $resolveStack);
             } elseif (is_array($refSchema) && array_key_exists($path, $refSchema)) {
@@ -180,6 +181,10 @@ public function resolveRefSchema($refSchema, $resolveStack = [])
             return $this->resolveRef($refSchema->{'$ref'}, $resolveStack);
         }
 
+        if (is_object($refSchema) && array_keys(get_object_vars($refSchema)) === ['']) {
+            $refSchema = $refSchema->{''};
+        }
+
         return $refSchema;
     }