first upload all files

Modules/Coupon/Checkers/ApplicableProducts.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace Modules\Coupon\Checkers;
+
+use Closure;
+use Modules\Cart\Facades\Cart;
+use Modules\Coupon\Exceptions\InapplicableCouponException;
+
+class ApplicableProducts
+{
+    public function handle($coupon, Closure $next)
+    {
+        $coupon->load('products');
+
+        if ($coupon->products->isEmpty()) {
+            return $next($coupon);
+        }
+
+        $cartItems = Cart::items()->filter(function ($cartItem) use ($coupon) {
+            return $coupon->products->contains($cartItem->product);
+        });
+
+        if ($cartItems->isEmpty()) {
+            throw new InapplicableCouponException;
+        }
+
+        return $next($coupon);
+    }
+}