chromium/third_party/blink/web_tests/http/tests/websocket/handshake-fail-by-unauthorized.html

<!DOCTYPE HTML>
<html>
<head>
<script src="/js-test-resources/js-test.js"></script>
</head>
<body>
<script>
description('Devtools should show error message when WebSocket handshake fails by HTTP 401 Unauthorized.')

window.jsTestIsAsync = true;

var url = "ws://localhost:8880/handshake-fail-by-unauthorized";
var ws = new WebSocket(url);

var isOpened = false;
var isClosed = false;
var isError = false;
var isTimedOut = false;

function endTest() {
    shouldBeFalse('isOpened');
    shouldBeTrue('isClosed');
    shouldBeTrue('isError');
    shouldBeFalse('isTimedOut');
    clearTimeout(timeoutID);
    finishJSTest();
}

ws.onopen = function() {
  isOpened = true;
}

ws.onclose = function() {
  isClosed = true;
  endTest();
}

ws.onerror = function(errorEvent) {
  isError = true;
}

var timeoutID = setTimeout(()=> {
  isTimedOut = true;
    endTest();
}, 3000);

</script>
</body>
</html>