navigation-api/updateCurrentEntry-method/basic.html

<!doctype html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<script>
async_test(t => {
  navigation.onnavigate = t.unreached_func("navigate must not fire");
  navigation.onnavigatesuccess = t.unreached_func("navigatesuccess must not fire");
  navigation.onnavigateerror = t.unreached_func("navigateerror must not fire");

  assert_equals(navigation.currentEntry.getState(), undefined, "Navigation API state starts out as undefined");
  assert_equals(history.state, null, "history.state starts out as null");

  const newState = { key: "value" };

  navigation.updateCurrentEntry({ state: newState });

  assert_equals(navigation.currentEntry.getState().key, "value");
  assert_not_equals(navigation.currentEntry.getState(), newState);
  assert_equals(history.state, null);

  // Wait a tick to make sure no events fire asynchronously.
  t.step_timeout(() => t.done(), 0);
}, "updateCurrentEntry() works as expected");
</script>