Allow passing prepared objects instead of array definition

Author: SilverFire

src/SpecBaseObject.php

@@ -121,9 +121,14 @@ public function __construct(array $data)
      */
     private function instantiate($type, $data)
     {
-        if (isset($data['$ref'])) {
+        if ($data instanceof $type) {
+            return $data;
+        }
+
+        if (is_array($data) && isset($data['$ref'])) {
             return new Reference($data, $type);
         }
+
         try {
             return new $type($data);
         } catch (\TypeError $e) {

src/spec/Paths.php

@@ -39,16 +39,24 @@ class Paths implements SpecObjectInterface, ArrayAccess, Countable, IteratorAggr
 
     /**
      * Create an object from spec data.
-     * @param array $data spec data read from YAML or JSON
+     * @param PathItem[]|array[] $data spec data read from YAML or JSON
      * @throws TypeErrorException in case invalid data is supplied.
      */
     public function __construct(array $data)
     {
         foreach ($data as $path => $object) {
             if ($object === null) {
                 $this->_paths[$path] = null;
-            } else {
+            } elseif (is_array($object)) {
                 $this->_paths[$path] = new PathItem($object);
+            } elseif ($object instanceof PathItem) {
+                $this->_paths[$path] = $object;
+            } else {
+                $givenType = gettype($object);
+                if ($givenType === 'object') {
+                    $givenType = get_class($object);
+                }
+                throw new \TypeError(sprintf('Path MUST be either array or PathItem object, "%s" given', $givenType));
             }
         }
     }

src/spec/Responses.php

@@ -42,7 +42,9 @@ public function __construct(array $data)
             // From Spec: This field MUST be enclosed in quotation marks (for example, "200") for compatibility between JSON and YAML.
             $statusCode = (string) $statusCode;
             if (preg_match('~^(?:default|[1-5](?:[0-9][0-9]|XX))$~', $statusCode)) {
-                if (isset($response['$ref'])) {
+                if ($response instanceof Response || $response instanceof Reference) {
+                    $this->_responses[$statusCode] = $response;
+                } elseif (isset($response['$ref'])) {
                     $this->_responses[$statusCode] = new Reference($response, Response::class);
                 } else {
                     $this->_responses[$statusCode] = new Response($response);