Capability to hook content prompt creation.

Author: hackademix

content/promptHook.js

@@ -0,0 +1,61 @@
+/*
+ * NoScript Commons Library
+ * Reusable building blocks for cross-browser security/privacy WebExtensions.
+ * Copyright (C) 2020-2023 Giorgio Maone <https://maone.net>
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ * 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/>.
+ */
+
+// depends on nscl/content/patchWindow.js
+"use strict";
+
+{
+  debug("Prompt Hook installation", document.URL); // DEV_ONLY
+  const patchPrompts = (scope, {port, xray}) => {
+    for (let methodName of ["alert", "confirm", "prompt"]) {
+      let target = methodName in scope.__proto__ ? scope.__proto__ : scope;
+      const method = xray.getSafeMethod(target, methodName);
+      const handler = cloneInto({
+        apply(targetObject, thisArg, argumentsList) {
+          try {
+            return method.call(thisArg, ...argumentsList);
+          } finally {
+            port.postMessage("prompt", target);
+          }
+        }
+      }, scope, {cloneFunctions: true});
+      target[methodName] = new scope.Proxy(method, handler);
+    }
+  };
+
+  const port = patchWindow(patchPrompts);
+  port.onMessage = (msg, {target}) => {
+    if (msg !== "prompt") return;
+    debug("Prompt Hook triggered by", target.location.href); // DEV_ONLY
+    function efs(w) {
+      try {
+        if (w.document.fullscreenElement) {
+          w.document.exitFullscreen();
+        }
+      } catch (e) {
+        debug(e); // DEV_ONLY
+      }
+    }
+    efs(window);
+    for (let j = 0; j in window; j++) {
+      efs(window[j]);
+    }
+  }
+}