From 8bda7a236f227b621f17eb4e7e6023f210134f8a Mon Sep 17 00:00:00 2001
From: HoJeong Go <seia@outlook.kr>
Date: Sun, 29 Mar 2026 11:07:58 +0900
Subject: [PATCH] optimise: utilise `Element.prototype.closest` for `:upward`

This tries to utilise `Element.prototype.closest` which is widely available: https://developer.mozilla.org/en-US/docs/Web/API/Element/closest for `:upward` pseudo-class.
---
 .../adblocker-extended-selectors/src/eval.ts  | 26 +++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/packages/adblocker-extended-selectors/src/eval.ts b/packages/adblocker-extended-selectors/src/eval.ts
index a4fc1fddb9..d3276a4e23 100644
--- a/packages/adblocker-extended-selectors/src/eval.ts
+++ b/packages/adblocker-extended-selectors/src/eval.ts
@@ -6,6 +6,7 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/.
  */
 
+import { classifySelector, SelectorType } from './extended.js';
 import type { AST, Complex, PseudoClass } from './types.js';
 
 const createXpathExpression = (function () {
@@ -23,6 +24,26 @@ const createXpathExpression = (function () {
   };
 })();
 
+const cachedIsExtended = (function () {
+  const extended: string[] = [];
+  const standard: string[] = [];
+
+  return function classify(selector: string) {
+    if (extended.includes(selector)) {
+      return true;
+    }
+    if (standard.includes(selector)) {
+      return false;
+    }
+    if (classifySelector(selector) === SelectorType.Extended) {
+      extended.push(selector);
+      return true;
+    }
+    standard.push(selector);
+    return false;
+  };
+})();
+
 /**
  * Evaluates an XPath expression and returns matching Element nodes.
  * @param element - The context element for XPath evaluation
@@ -365,6 +386,11 @@ function transpose(element: Element, selector: AST): Element[] | null {
             return [parentElement];
           }
         }
+      } else if (cachedIsExtended(argument) === false) {
+        const closest = element.closest(argument);
+        if (closest !== null) {
+          return [closest];
+        }
       } else {
         while ((parentElement = parentElement.parentElement) !== null) {
           if (parentElement.matches(argument)) {