| <!DOCTYPE html> |
| <meta charset="utf-8"> |
| <title>[[PreventExtensions]] on a WindowProxy object should return false</title> |
| <link rel="help" href="https://html.spec.whatwg.org/multipage/window-object.html#windowproxy-preventextensions"> |
| |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| |
| <script> |
| "use strict"; |
| |
| test(() => { |
| assert_throws_js(TypeError, () => { |
| Object.preventExtensions(window); |
| }); |
| }, "Object.preventExtensions throws a TypeError"); |
| |
| test(() => { |
| assert_false(Reflect.preventExtensions(window)); |
| }, "Reflect.preventExtensions returns false"); |
| </script> |
