ACP2E-3710: move validator extension to mage/validation.

Author: alzota

lib/web/mage/validation.js

@@ -15,6 +15,23 @@ define([
 
     var creditCartTypes, rules, showLabel, originValidateDelegate;
 
+    if ($.validator) {
+        let originalErrorsFor = $.validator.prototype.errorsFor;
+
+        $.validator.prototype.errorsFor = function (element) {
+            let name = this.escapeCssMeta(this.idOrName(element)),
+                describer = $(element).attr('aria-describedby'),
+                selector = `label[for='${name}'], label[for='${name}'] *`;
+
+            // 'aria-describedby' should directly reference the error element
+            if (describer) {
+                selector += `, #${this.escapeCssMeta(describer).replace(/\s+/g, ', #')}`;
+                selector += ':visible';
+            }
+            return originalErrorsFor.call(this, element).add(this.errors().filter(selector));
+        };
+    }
+
     $.extend(true, $, {
         // @TODO: Move methods 'isEmpty', 'isEmptyNoTrim', 'parseNumber', 'stripHtml' in file with utility functions
         mage: {