From 5f08bc2aa0e830b356dda148325109f5e46ed60a Mon Sep 17 00:00:00 2001
From: Jonas Porto <jporto.contato@hotmail.com>
Date: Thu, 29 Oct 2026 20:15:35 -0300
Subject: [PATCH] fix: native functions read through window run with the global
 as receiver (#345)

---
 cjs/interface/document.js | 18 +++++++++++++++---
 esm/interface/document.js | 18 +++++++++++++++---
 test/html/document.js     |  7 +++++++
 3 files changed, 37 insertions(+), 6 deletions(-)

diff --git a/cjs/interface/document.js b/cjs/interface/document.js
index 1a92fb28..32f2a7a0 100644
--- a/cjs/interface/document.js
+++ b/cjs/interface/document.js
@@ -34,6 +34,13 @@ const {Range} = require('./range.js');
 const {Text} = require('./text.js');
 const {TreeWalker} = require('./tree-walker.js');
 
+const boundGlobals = new WeakMap;
+const boundGlobal = fn => {
+  if (!boundGlobals.has(fn))
+    boundGlobals.set(fn, fn.bind(globalThis));
+  return boundGlobals.get(fn);
+};
+
 const query = (method, ownerDocument, selectors) => {
   let {[NEXT]: next, [END]: end} = ownerDocument;
   return method.call({ownerDocument, [NEXT]: next, [END]: end}, selectors);
@@ -130,9 +137,14 @@ class Document extends NonElementParentNode {
                 this[MUTATION_OBSERVER] = new MutationObserverClass(this);
               return this[MUTATION_OBSERVER].class;
           }
-          return (this[GLOBALS] && this[GLOBALS][name]) ||
-                  globalExports[name] ||
-                  globalThis[name];
+          const value = (this[GLOBALS] && this[GLOBALS][name]) ||
+                        globalExports[name] ||
+                        globalThis[name];
+          // a native function called through the proxy runs with the proxy
+          // as receiver, which browsers reject ("Illegal invocation"):
+          // bind it to the global, once, and leave constructors as they are
+          return typeof value === 'function' && !('prototype' in value) && value === globalThis[name] ?
+                  boundGlobal(value) : value;
         }
       }));
     return window.get(this);
diff --git a/esm/interface/document.js b/esm/interface/document.js
index d68c9eb5..3cb3777b 100644
--- a/esm/interface/document.js
+++ b/esm/interface/document.js
@@ -34,6 +34,13 @@ import {Range} from './range.js';
 import {Text} from './text.js';
 import {TreeWalker} from './tree-walker.js';
 
+const boundGlobals = new WeakMap;
+const boundGlobal = fn => {
+  if (!boundGlobals.has(fn))
+    boundGlobals.set(fn, fn.bind(globalThis));
+  return boundGlobals.get(fn);
+};
+
 const query = (method, ownerDocument, selectors) => {
   let {[NEXT]: next, [END]: end} = ownerDocument;
   return method.call({ownerDocument, [NEXT]: next, [END]: end}, selectors);
@@ -130,9 +137,14 @@ export class Document extends NonElementParentNode {
                 this[MUTATION_OBSERVER] = new MutationObserverClass(this);
               return this[MUTATION_OBSERVER].class;
           }
-          return (this[GLOBALS] && this[GLOBALS][name]) ||
-                  globalExports[name] ||
-                  globalThis[name];
+          const value = (this[GLOBALS] && this[GLOBALS][name]) ||
+                        globalExports[name] ||
+                        globalThis[name];
+          // a native function called through the proxy runs with the proxy
+          // as receiver, which browsers reject ("Illegal invocation"):
+          // bind it to the global, once, and leave constructors as they are
+          return typeof value === 'function' && !('prototype' in value) && value === globalThis[name] ?
+                  boundGlobal(value) : value;
         }
       }));
     return window.get(this);
diff --git a/test/html/document.js b/test/html/document.js
index b5e15062..066947e9 100644
--- a/test/html/document.js
+++ b/test/html/document.js
@@ -70,6 +70,13 @@ assert(window.addEventListener, null);
 
 assert(typeof window.performance.now(), 'number');
 
+// https://github.com/WebReflection/linkedom/issues/345
+globalThis.receiver = {receiver() { return this; }}.receiver;
+assert(window.receiver() === globalThis, true, 'a native function runs with the global as receiver');
+assert(window.receiver === window.receiver, true, 'bound once');
+assert(window.URL === URL, true, 'constructors keep their identity');
+delete globalThis.receiver;
+
 assert(parseHTML('<html><body><div>asdf</div></body></html>').document.body.outerHTML, '<body><div>asdf</div></body>');
 
 const location = {href: 'http://ok'};