I have added a plugin which should be triggered when a coupon code is applied. Sadly nothing happens, no errors too.

Where did I go wrong?


namespace Zygis\TestModule\Plugin;

class CheckoutCouponApply {

    public function beforeSet(\Magento\Quote\Model\CouponManagement $subject, $cartId, $couponCode)
        $objectManager = \Magento\Framework\App\ObjectManager::getInstance();
        $logger        = $objectManager->create('\Psr\Log\LoggerInterface');
        $logger->debug('test before set');

    public function afterSet(\Magento\Quote\Model\CouponManagement $subject, $cartId, $couponCode)
        $objectManager = \Magento\Framework\App\ObjectManager::getInstance();
        $logger        = $objectManager->create('\Psr\Log\LoggerInterface');
        $logger->debug('test after set');

And obviously I got it registered in Zygis\TestModule\etc\frontend\di.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <type name="Magento\Quote\Model\CouponManagement">
        <plugin name="CheckoutCouponApply" type="Zygis\TestModule\Plugin\CheckoutCouponApply" sortOrder="1" />

Any help is appreciated! Thanks!

  • Sadly you are on the wrong path for coupone code. What is your primary goal for plugin?
    – Keyur Shah
    Jul 28, 2016 at 9:20
  • I want to change the error message for an expired coupon code later. However now I just want to see the plugin being fired. Please elaborate why I'm on the wrong path? Jul 28, 2016 at 9:25
  • I have found the right way. I created a preference instead of plugin. Jul 28, 2016 at 12:44
  • Did you found the solution using plugin way? Jul 8, 2019 at 6:11

1 Answer 1


If anybody stumbles across this in the future, make sure your di.xml file for the REST endpoints resides in the etc directory, not the etc/frontend directory.





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