access-control-preflight-async-method-denied.htm

<!DOCTYPE html>
<html>
  <head>
    <title>Async request denied at preflight because of non-CORS-safelisted method</title>
    <script src="/resources/testharness.js"></script>
    <script src="/resources/testharnessreport.js"></script>
    <script src="/common/get-host-info.sub.js"></script>
    <script src="/common/utils.js"></script>
  </head>
  <body>
    <script type="text/javascript">
    const uuid = token();
    const url = get_host_info().HTTP_REMOTE_ORIGIN +
          "/xhr/resources/access-control-preflight-denied.py?token=" + uuid;

    async_test((test) => {
      let xhr = new XMLHttpRequest;
      xhr.open("GET", url + "&command=reset", false);
      xhr.send();

      xhr = new XMLHttpRequest;
      xhr.open("DELETE", url + "&command=method", true);

      xhr.onload = test.unreached_func(
          "Cross-domain access with non-CORS-safelisted method allowed without throwing exception");

      xhr.onerror = test.step_func_done(() => {
        xhr = new XMLHttpRequest;
        xhr.open("GET", url + "&command=complete", false);
        xhr.send();
        assert_equals(xhr.responseText, "Request successfully blocked.");
      });

      xhr.send();
    }, "Async request denied at preflight");
    </script>
  </body>
</html>

chromium/third_party/blink/web_tests/external/wpt/xhr/access-control-preflight-async-method-denied.htm