chromium/third_party/blink/web_tests/external/wpt/websockets/interfaces/WebSocket/close/close-multiple.html

<!doctype html>
<title>WebSockets: close() several times</title>
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>
<script src=../../../constants.sub.js></script>
<meta name="variant" content="?default">
<meta name="variant" content="?wss">
<div id=log></div>
<script>
var i = 0;
async_test(function(t) {
  var ws = new WebSocket(SCHEME_DOMAIN_PORT+'/');
  ws.onclose = t.step_func(function(e) {
    i++;
  });
  ws.close();
  ws.close();
  ws.close();
  var f = t.step_func(function() {
    if (i < 1) {
      t.step_timeout(f, 500);
      return;
    }
    assert_equals(i, 1);
    t.done()
  });
  t.step_timeout(f, 500);
});
</script>