Improve prevent-addEventListener scriptlet

gorhill · gorhill · commit 1977196abe83 · 2025-12-18T09:03:36.000-05:00
diff --git a/src/js/resources/prevent-addeventlistener.js b/src/js/resources/prevent-addeventlistener.js
@@ -0,0 +1,158 @@
+/*******************************************************************************
+
+    uBlock Origin - a comprehensive, efficient content blocker
+    Copyright (C) 2019-present Raymond Hill
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see {https://www.gnu.org/licenses/}.
+
+    Home: https://github.com/gorhill/uBlock
+
+*/
+
+import { proxyApplyFn } from './proxy-apply.js';
+import { registerScriptlet } from './base.js';
+import { runAt } from './run-at.js';
+import { safeSelf } from './safe-self.js';
+
+/******************************************************************************/
+
+/**
+ * @scriptlet prevent-addEventListener
+ * 
+ * @description
+ * Conditionally prevent execution of the callback function passed to native
+ * addEventListener method. With no parameters, all calls to addEventListener
+ * will be shown in the logger.
+ * 
+ * @param [type]
+ * The type of the event to prevent. The pattern can be a plain string, or a
+ * regex to specify more than one event type.
+ * 
+ * @param [pattern]
+ * A pattern to match against the stringified callback. The pattern can be a
+ * plain string, or a regex.
+ * 
+ * @param [runat, value]
+ * An optional vararg which tell the scriptlet when the prevention should
+ * start. Values correspond to `readyState`: loading, interactive, complete.
+ * 
+ * @param [protect, 1]
+ * An optional vararg which tells the scriptlet whether the prevention should
+ * be protected, i.e. not overwritten by other code.
+ * 
+ * */
+
+function preventAddEventListener(
+    type = '',
+    pattern = ''
+) {
+    const safe = safeSelf();
+    const extraArgs = safe.getExtraArgs(Array.from(arguments), 2);
+    const logPrefix = safe.makeLogPrefix('prevent-addEventListener', type, pattern);
+    const reType = safe.patternToRegex(type, undefined, true);
+    const rePattern = safe.patternToRegex(pattern);
+    const targetSelector = extraArgs.elements || undefined;
+    const elementMatches = elem => {
+        if ( targetSelector === 'window' ) { return elem === window; }
+        if ( targetSelector === 'document' ) { return elem === document; }
+        if ( elem && elem.matches && elem.matches(targetSelector) ) { return true; }
+        const elems = Array.from(document.querySelectorAll(targetSelector));
+        return elems.includes(elem);
+    };
+    const elementDetails = elem => {
+        if ( elem instanceof Window ) { return 'window'; }
+        if ( elem instanceof Document ) { return 'document'; }
+        if ( elem instanceof Element === false ) { return '?'; }
+        const parts = [];
+        // https://github.com/uBlockOrigin/uAssets/discussions/17907#discussioncomment-9871079
+        const id = String(elem.id);
+        if ( id !== '' ) { parts.push(`#${CSS.escape(id)}`); }
+        for ( let i = 0; i < elem.classList.length; i++ ) {
+            parts.push(`.${CSS.escape(elem.classList.item(i))}`);
+        }
+        for ( let i = 0; i < elem.attributes.length; i++ ) {
+            const attr = elem.attributes.item(i);
+            if ( attr.name === 'id' ) { continue; }
+            if ( attr.name === 'class' ) { continue; }
+            parts.push(`[${CSS.escape(attr.name)}="${attr.value}"]`);
+        }
+        return parts.join('');
+    };
+    const shouldPrevent = (thisArg, type, handler) => {
+        const matchesType = safe.RegExp_test.call(reType, type);
+        const matchesHandler = safe.RegExp_test.call(rePattern, handler);
+        const matchesEither = matchesType || matchesHandler;
+        const matchesBoth = matchesType && matchesHandler;
+        if ( safe.logLevel > 1 && matchesEither ) {
+            debugger; // eslint-disable-line no-debugger
+        }
+        if ( matchesBoth && targetSelector !== undefined ) {
+            if ( elementMatches(thisArg) === false ) { return false; }
+        }
+        return matchesBoth;
+    };
+    const proxyFn = function(context) {
+        const { callArgs, thisArg } = context;
+        let t, h;
+        try {
+            t = String(callArgs[0]);
+            if ( typeof callArgs[1] === 'function' ) {
+                h = String(safe.Function_toString(callArgs[1]));
+            } else if ( typeof callArgs[1] === 'object' && callArgs[1] !== null ) {
+                if ( typeof callArgs[1].handleEvent === 'function' ) {
+                    h = String(safe.Function_toString(callArgs[1].handleEvent));
+                }
+            } else {
+                h = String(callArgs[1]);
+            }
+        } catch {
+        }
+        if ( type === '' && pattern === '' ) {
+            safe.uboLog(logPrefix, `Called: ${t}\n${h}\n${elementDetails(thisArg)}`);
+        } else if ( shouldPrevent(thisArg, t, h) ) {
+            return safe.uboLog(logPrefix, `Prevented: ${t}\n${h}\n${elementDetails(thisArg)}`);
+        }
+        return context.reflect();
+    };
+    runAt(( ) => {
+        proxyApplyFn('EventTarget.prototype.addEventListener', proxyFn);
+        if ( extraArgs.protect ) {
+            const { addEventListener } = EventTarget.prototype;
+            Object.defineProperty(EventTarget.prototype, 'addEventListener', {
+                set() { },
+                get() { return addEventListener; }
+            });
+        }
+        proxyApplyFn('document.addEventListener', proxyFn);
+        if ( extraArgs.protect ) {
+            const { addEventListener } = document;
+            Object.defineProperty(document, 'addEventListener', {
+                set() { },
+                get() { return addEventListener; }
+            });
+        }
+    }, extraArgs.runAt);
+}
+registerScriptlet(preventAddEventListener , {
+    name: 'prevent-addEventListener.js',
+    aliases: [
+        'addEventListener-defuser.js',
+        'aeld.js',
+    ],
+    dependencies: [
+        proxyApplyFn,
+        runAt,
+        safeSelf,
+    ],
+});
diff --git a/src/js/resources/scriptlets.js b/src/js/resources/scriptlets.js
@@ -27,6 +27,7 @@ import './json-edit.js';
 import './json-prune.js';
 import './noeval.js';
 import './object-prune.js';
+import './prevent-addeventlistener.js';
 import './prevent-dialog.js';
 import './prevent-fetch.js';
 import './prevent-innerHTML.js';
@@ -701,102 +702,6 @@ function abortOnPropertyWrite(
 
 /******************************************************************************/
 
-builtinScriptlets.push({
-    name: 'addEventListener-defuser.js',
-    aliases: [
-        'aeld.js',
-        'prevent-addEventListener.js',
-    ],
-    fn: addEventListenerDefuser,
-    dependencies: [
-        'proxy-apply.fn',
-        'run-at.fn',
-        'safe-self.fn',
-        'should-debug.fn',
-    ],
-});
-// https://github.com/uBlockOrigin/uAssets/issues/9123#issuecomment-848255120
-function addEventListenerDefuser(
-    type = '',
-    pattern = ''
-) {
-    const safe = safeSelf();
-    const extraArgs = safe.getExtraArgs(Array.from(arguments), 2);
-    const logPrefix = safe.makeLogPrefix('prevent-addEventListener', type, pattern);
-    const reType = safe.patternToRegex(type, undefined, true);
-    const rePattern = safe.patternToRegex(pattern);
-    const debug = shouldDebug(extraArgs);
-    const targetSelector = extraArgs.elements || undefined;
-    const elementMatches = elem => {
-        if ( targetSelector === 'window' ) { return elem === window; }
-        if ( targetSelector === 'document' ) { return elem === document; }
-        if ( elem && elem.matches && elem.matches(targetSelector) ) { return true; }
-        const elems = Array.from(document.querySelectorAll(targetSelector));
-        return elems.includes(elem);
-    };
-    const elementDetails = elem => {
-        if ( elem instanceof Window ) { return 'window'; }
-        if ( elem instanceof Document ) { return 'document'; }
-        if ( elem instanceof Element === false ) { return '?'; }
-        const parts = [];
-        // https://github.com/uBlockOrigin/uAssets/discussions/17907#discussioncomment-9871079
-        const id = String(elem.id);
-        if ( id !== '' ) { parts.push(`#${CSS.escape(id)}`); }
-        for ( let i = 0; i < elem.classList.length; i++ ) {
-            parts.push(`.${CSS.escape(elem.classList.item(i))}`);
-        }
-        for ( let i = 0; i < elem.attributes.length; i++ ) {
-            const attr = elem.attributes.item(i);
-            if ( attr.name === 'id' ) { continue; }
-            if ( attr.name === 'class' ) { continue; }
-            parts.push(`[${CSS.escape(attr.name)}="${attr.value}"]`);
-        }
-        return parts.join('');
-    };
-    const shouldPrevent = (thisArg, type, handler) => {
-        const matchesType = safe.RegExp_test.call(reType, type);
-        const matchesHandler = safe.RegExp_test.call(rePattern, handler);
-        const matchesEither = matchesType || matchesHandler;
-        const matchesBoth = matchesType && matchesHandler;
-        if ( debug === 1 && matchesBoth || debug === 2 && matchesEither ) {
-            debugger; // eslint-disable-line no-debugger
-        }
-        if ( matchesBoth && targetSelector !== undefined ) {
-            if ( elementMatches(thisArg) === false ) { return false; }
-        }
-        return matchesBoth;
-    };
-    const proxyFn = function(context) {
-        const { callArgs, thisArg } = context;
-        let t, h;
-        try {
-            t = String(callArgs[0]);
-            if ( typeof callArgs[1] === 'function' ) {
-                h = String(safe.Function_toString(callArgs[1]));
-            } else if ( typeof callArgs[1] === 'object' && callArgs[1] !== null ) {
-                if ( typeof callArgs[1].handleEvent === 'function' ) {
-                    h = String(safe.Function_toString(callArgs[1].handleEvent));
-                }
-            } else {
-                h = String(callArgs[1]);
-            }
-        } catch {
-        }
-        if ( type === '' && pattern === '' ) {
-            safe.uboLog(logPrefix, `Called: ${t}\n${h}\n${elementDetails(thisArg)}`);
-        } else if ( shouldPrevent(thisArg, t, h) ) {
-            return safe.uboLog(logPrefix, `Prevented: ${t}\n${h}\n${elementDetails(thisArg)}`);
-        }
-        return context.reflect();
-    };
-    runAt(( ) => {
-        proxyApplyFn('EventTarget.prototype.addEventListener', proxyFn);
-        proxyApplyFn('document.addEventListener', proxyFn);
-    }, extraArgs.runAt);
-}
-
-/******************************************************************************/
-
 builtinScriptlets.push({
     name: 'adjust-setInterval.js',
     aliases: [
