chromium/third_party/blink/web_tests/external/wpt/xhr/responseurl.html

<!doctype html>
<html>
  <head>
    <title>XMLHttpRequest: responseURL test</title>
    <script src="/resources/testharness.js"></script>
    <script src="/resources/testharnessreport.js"></script>
    <link rel="help" href="https://xhr.spec.whatwg.org/#the-responseurl-attribute"/>
  </head>
  <body>
    <div id="log"></div>
    <script>
      test(function() {
        var client = new XMLHttpRequest()
        assert_equals(client.responseURL, "")

        client.open("GET", "foo.html", false)
        client.send()

        expected = location.href.replace(/[^/]*$/, 'foo.html')
        assert_equals(client.status, 404)
        assert_equals(client.responseURL, expected)
      }, "404 response has proper responseURL")
      test(function() {
        var client = new XMLHttpRequest()
        assert_equals(client.responseURL, "")

        target = "image.gif"
        client.open("GET", "resources/redirect.py?location=" + target, false)
        client.send()

        expected = location.href.replace(/[^/]*$/, "resources/" + target)
        assert_equals(client.status, 200)
        assert_equals(client.responseURL, expected)
      }, "Redirected response has proper responseURL")
    </script>
  </body>
</html>