Feature: Updating Listreners, Separating Logic from listeners, Queuing Policies

src/Order/Services/OrderStatusFlow.php

@@ -133,6 +133,22 @@ class OrderStatusFlow
         return ! $order->paid && $this->isCod($order);
     }
 
+    /**
+     * Whether moving $order to $to is a valid transition from its CURRENT
+     * status — the single source of truth for "is this a legal next step,"
+     * so a caller reacting to an external event (a carrier tracking
+     * checkpoint, a staff action) doesn't need to hardcode its own "only
+     * fire from status X" guard duplicating what nextOptions() already
+     * knows. See e.g. Modules\Core\Order\Listeners\
+     * AdvanceFulfillmentOnCarrierCheckpoint, which used to compare
+     * $order->status to a literal 'ready_for_dispatch' inline instead of
+     * asking this class.
+     */
+    public function isValidTransition(Order $order, string $to): bool
+    {
+        return array_key_exists($to, $this->nextOptions($order));
+    }
+
     private function label(string $status): string
     {
         return (string) str($status)->replace('_', ' ')->title();