Override helper in Magento 2?

Question

I'm trying override getBreadcrumbPath() in Magento\Catalog\Helper\Data.

In di.xml

<type name="Magento\Catalog\Helper\Data">
    <plugin name="Helper" type="XXX\YYY\Plugin\Helper\Data" sortOrder="10"/>
</type>

In plugin

public function aroundGetBreadcrumbPath(\Magento\Catalog\Helper\Data $subject, callable $proceed)
{
echo "hi";exit;
}

But its not working

Answer 1

1.Create file di.xml inside Vendor/Module/etc

 <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
<type name="Magento\Catalog\Helper\Data">
    <plugin name="catalog-helper-data" type="Vendor\Module\Plugin\Data" />
</type>

2.Create file Data.php inside Vendor/Module/Plugin

<?php
namespace Vendor\Module\Plugin;
class Data
{
public function aroundGetBreadcrumbPath(\Magento\Catalog\Helper\Data $subject, callable $proceed)
    {
        echo "hi";exit;  
    }
}
?>

Answer 2

An around plugin needs to always have a return value. The return value should be something like:

$result = $proceed(PARAMETERS FROM THE ORIGINAL FUNCTION);

You can look at the documentation here.

Not sure if there is more that you are missing.

Does your di.xml also start with the following?

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">