Types are now serializable to JSON (output their name)

src/Type/Definition/Type.php

@@ -16,7 +16,7 @@ GraphQLInputObjectType |
 GraphQLList |
 GraphQLNonNull;
 */
-abstract class Type
+abstract class Type implements \JsonSerializable
 {
     const STRING = 'String';
     const INT = 'Int';
@@ -250,6 +250,14 @@ abstract class Type
         return $this->name;
     }
 
+    /**
+     * @return string
+     */
+    public function jsonSerialize()
+    {
+        return $this->toString();
+    }
+
     /**
      * @return string
      */