feat: add HasCart trait and ShareCartWithInertia

src/Concerns/ShareCartWithInertia.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Wearepixel\Cart\Concerns;
+
+use Wearepixel\Cart\Cart;
+
+class ShareCartWithInertia
+{
+    public static function data(?Cart $cart = null): array
+    {
+        $cart ??= app('cart');
+
+        return [
+            'items'    => $cart->getContent()->toArray(),
+            'subtotal' => (float) $cart->getSubTotal(false),
+            'total'    => (float) $cart->getTotal(),
+            'count'    => (int) $cart->getTotalQuantity(),
+        ];
+    }
+}