Magento 2 Product – Where to Find Product View Page?

Go to file path, vendor/magento/module-checkout/view/frontend/web/js/view/minicart.js

check below part for close button html like,

<button type="button" id="btn-minicart-close" class="action close" data-action="close" data-bind="attr: { title: $t('Close') }" title="Close">
        <span><!-- ko i18n: 'Close' --><span>Close</span><!-- /ko --></span>
    </button>

For close button html in minicart above display we can find data-action="close" from js file.

closeSidebar: function() {
            var minicart = $('[data-block="minicart"]');
            minicart.on('click', '[data-action="close"]', function(event) {
                event.stopPropagation();
                minicart.find('[data-role="dropdownDialog"]').dropdownDialog("close");
            });
            return true;
        }

Here list of url for checkout, update button, login url, remove button

 "url": {
            "checkout": window.checkout.checkoutUrl,
            "update": window.checkout.updateItemQtyUrl,
            "remove": window.checkout.removeItemUrl,
            "loginUrl": window.checkout.customerLoginUrl,
            "isRedirectRequired": window.checkout.isRedirectRequired
        },
        "button": {
            "checkout": "#top-cart-btn-checkout",
            "remove": "#mini-cart a.action.delete",
            "close": "#btn-minicart-close"
        }

Try with below solutions, Replace _ with folder and separate each folder path like below,

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
   <preference for="Magento\Catalog\Block\Product\View" type="Magento\Module\Inject\Session\Block\Product\View"/>
</config>

Set your block php file at below location,

app/code/Magento/Module/Inject/Session/Block/Product/View.php

inside php file,

<?php
namespace  Magento\Module\Inject\Session\Block\Product;

class View extends \Magento\Catalog\Block\Product\View{

    //your custom code.....

}