src/third_party/web_platform_tests/websockets/security/002.html

<!doctype html>
<title>WebSockets: check Sec-WebSocket-Key</title>
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>
<script src=../constants.js?pipe=sub></script>
<div id=log></div>
<script>
async_test(function(t) {
  var xhr = new XMLHttpRequest();
  xhr.onload = t.step_func(function() {
    assert_equals(xhr.responseText, 'PASS');
    t.done();
  });
  xhr.open("GET", "check.py", true);
  xhr.setRequestHeader('Sec-WebSocket-Key', 'jW7qmdXj5Kk5jTClF1BN3');
  xhr.send(null);
});
</script>