[mv3] Add support for abort-on-property-read scriptlet

Author: gorhill

platform/mv3/scriptlets/abort-on-property-read.js

@@ -0,0 +1,132 @@
+/*******************************************************************************
+
+    uBlock Origin - a browser extension to block requests.
+    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 {http://www.gnu.org/licenses/}.
+
+    Home: https://github.com/gorhill/uBlock
+
+    The scriptlets below are meant to be injected only into a
+    web page context.
+*/
+
+/* jshint esversion:11 */
+
+'use strict';
+
+/******************************************************************************/
+
+/// name abort-on-property-read
+/// alias aopr
+
+/******************************************************************************/
+
+// Important!
+// Isolate from global scope
+(function() {
+
+/******************************************************************************/
+
+const ObjGetOwnPropertyDescriptor = Object.getOwnPropertyDescriptor;
+const ObjDefineProperty = Object.defineProperty;
+
+const magic =
+    String.fromCharCode(Date.now() % 26 + 97) +
+    Math.floor(Math.random() * 982451653 + 982451653).toString(36);
+
+const abort = function() {
+    throw new ReferenceError(magic);
+};
+
+const makeProxy = function(owner, chain) {
+    const pos = chain.indexOf('.');
+    if ( pos === -1 ) {
+        const desc = ObjGetOwnPropertyDescriptor(owner, chain);
+        if ( !desc || desc.get !== abort ) {
+            ObjDefineProperty(owner, chain, {
+                get: abort,
+                set: function(){}
+            });
+        }
+        return;
+    }
+
+    const prop = chain.slice(0, pos);
+    let v = owner[prop];
+    chain = chain.slice(pos + 1);
+    if ( v ) {
+        makeProxy(v, chain);
+        return;
+    }
+
+    const desc = ObjGetOwnPropertyDescriptor(owner, prop);
+    if ( desc && desc.set !== undefined ) { return; }
+
+    ObjDefineProperty(owner, prop, {
+        get: function() { return v; },
+        set: function(a) {
+            v = a;
+            if ( a instanceof Object ) {
+                makeProxy(a, chain);
+            }
+        }
+    });
+};
+
+const scriptlet = (
+    chain = ''
+) => {
+    const owner = window;
+    makeProxy(owner, chain);
+    const oe = window.onerror;
+    window.onerror = function(msg, src, line, col, error) {
+        if ( typeof msg === 'string' && msg.indexOf(magic) !== -1 ) {
+            return true;
+        }
+        if ( oe instanceof Function ) {
+            return oe(msg, src, line, col, error);
+        }
+    }.bind();
+};
+
+/******************************************************************************/
+
+const argsMap = new Map(self.$argsMap$);
+
+const hostnamesMap = new Map(self.$hostnamesMap$);
+
+let hn;
+try { hn = document.location.hostname; } catch(ex) { }
+while ( hn ) {
+    if ( hostnamesMap.has(hn) ) {
+        let argsHashes = hostnamesMap.get(hn);
+        if ( typeof argsHashes === 'number' ) { argsHashes = [ argsHashes ]; }
+        for ( const argsHash of argsHashes ) {
+            const details = argsMap.get(argsHash);
+            if ( details.n && details.n.includes(hn) ) { continue; }
+            try { scriptlet(...details.a); } catch(ex) {}
+        }
+    }
+    const pos = hn.indexOf('.');
+    if ( pos === -1 ) { break; }
+    hn = hn.slice(pos + 1);
+}
+
+/******************************************************************************/
+
+})();
+
+/******************************************************************************/
+