navigation-api/focus-reset/change-focus-during-intercept.html

<!doctype html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<body>
<script>
promise_test(async t => {
  let intercept_resolve;
  navigation.addEventListener("navigate", e => {
    e.intercept({ handler: () => new Promise(resolve => intercept_resolve = resolve),
                  focusReset: "after-transition" });
  }, { once: true });

  const button = document.body.appendChild(document.createElement("button"));
  const button2 = document.body.appendChild(document.createElement("button"));
  button2.tabIndex = 0;
  t.add_cleanup(() => {
    button.remove();
    button2.remove();
  });

  assert_equals(document.activeElement, document.body, "Start on body");
  button.focus();
  assert_equals(document.activeElement, button, "focus() worked");

  const finished = navigation.navigate("#1").finished;
  button2.focus();
  assert_equals(document.activeElement, button2, "focus() worked");

  intercept_resolve();
  await finished;
  assert_equals(document.activeElement, button2, "Focus was not reset after the transition");
}, "");
</script>
</body>