| <!DOCTYPE html> |
| <meta charset="utf-8"> |
| <title>EventTarget's addEventListener + removeEventListener</title> |
| <link rel="author" title="Sebastian Mayr" href="mailto:wpt@smayr.name"> |
| <link rel="help" href="https://dom.spec.whatwg.org/#dom-eventtarget-addeventlistener"> |
| <link rel="help" href="https://dom.spec.whatwg.org/#dom-eventtarget-removeeventlistener"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <div id="log"></div> |
| <script> |
| "use strict"; |
| |
| function listener(evt) { |
| evt.preventDefault(); |
| return false; |
| } |
| |
| test(() => { |
| document.addEventListener("x", listener, false); |
| let event = new Event("x", { cancelable: true }); |
| let ret = document.dispatchEvent(event); |
| assert_false(ret); |
| |
| document.removeEventListener("x", listener); |
| event = new Event("x", { cancelable: true }); |
| ret = document.dispatchEvent(event); |
| assert_true(ret); |
| }, "Removing an event listener without explicit capture arg should succeed"); |
| </script> |