BUGFIX: Ensure referential equality of two connection types in new Gr…

…aphQL 4 compatible node/edges implementation

src/Pagination/Connection.php

@@ -51,6 +51,12 @@ class Connection implements OperationResolver
      */
     protected $connectedType;
 
+    /**
+     * Cache the instance of the connection type to guarantee referential equality for graphql-php
+     * @var ObjectType
+     */
+    protected $connectionTypeInstance;
+
     /**
      * @var string
      */
@@ -122,13 +128,21 @@ public function setConnectionType($type)
      * Evaluate Connection type
      *
      * @param bool $evaluate
+     * @param bool $useCache When true, rely on the previous instance created
      * @return ObjectType|Callable
      */
-    public function getConnectionType($evaluate = true)
+    public function getConnectionType($evaluate = true, $useCache = true)
     {
-        return ($evaluate && is_callable($this->connectedType))
+        if ($useCache && $this->connectionTypeInstance) {
+            return $this->connectionTypeInstance;
+        }
+        $instance = ($evaluate && is_callable($this->connectedType))
             ? call_user_func($this->connectedType)
             : $this->connectedType;
+
+        $this->connectionTypeInstance = $instance;
+
+        return $this->connectionTypeInstance;
     }
 
     /**