Fix: Resolving box now by instance, not by type. Also, fixing bug where missing shipping driver would break checkout

src/Shipping/Support/BoxNowShipping.php

@@ -0,0 +1,53 @@
+<?php
+
+namespace Modules\Core\Shipping\Support;
+
+use Lunar\Shipping\Facades\Shipping;
+use Lunar\Shipping\Models\ShippingMethod;
+use Modules\Core\Shipping\Carriers\BoxNow\BoxNowRateDriver;
+
+/**
+ * Whether something is Box Now — a checkout option, a shipping method, a
+ * driver key — by checking that the driver is a BoxNowRateDriver, never by
+ * comparing names: an option's identifier is the merchant-typed method
+ * code (may well not be "box-now"), and the driver may be registered under
+ * any key.
+ */
+class BoxNowShipping
+{
+    public static function isOption(?string $identifier): bool
+    {
+        return $identifier !== null
+            && self::isMethod(ShippingMethod::where('code', $identifier)->first());
+    }
+
+    public static function isMethod(?ShippingMethod $method): bool
+    {
+        return self::isDriver($method?->driver);
+    }
+
+    /**
+     * A shipping driver key (a method's `driver`, a shipment's `carrier`)
+     * that resolves to Box Now. getSupportedDrivers() rather than
+     * Shipping::driver(), which throws for a key no longer registered.
+     */
+    public static function isDriver(?string $driver): bool
+    {
+        return $driver !== null
+            && Shipping::getSupportedDrivers()->get($driver) instanceof BoxNowRateDriver;
+    }
+
+    /**
+     * Codes of every Box Now shipping method — for marking options in bulk.
+     *
+     * @return array<int, string>
+     */
+    public static function codes(): array
+    {
+        return ShippingMethod::all()
+            ->filter(fn (ShippingMethod $method) => self::isMethod($method))
+            ->pluck('code')
+            ->values()
+            ->all();
+    }
+}