css/mediaqueries/display-mode.html

<!DOCTYPE html>
<link rel="help" href="http://www.w3.org/TR/mediaqueries-5/#display-mode" />
<script type="text/javascript" src="/resources/testharness.js"></script>
<script type="text/javascript" src="/resources/testharnessreport.js"></script>
<script type="text/javascript" src="resources/matchmedia-utils.js"></script>
<script>
  query_should_be_known("(display-mode)");
  query_should_be_known("(display-mode: standalone)");
  query_should_be_known("(display-mode: browser)");
  query_should_be_known("(display-mode: minimal-ui)");
  query_should_be_known("(display-mode: fullscreen)");
  query_should_be_known("(display-mode: picture-in-picture)");

  query_should_be_unknown("(display-mode: 0)");
  query_should_be_unknown("(display-mode: none)");
  query_should_be_unknown("(display-mode: random)");
  query_should_be_unknown("(display-mode: 10px)");
  query_should_be_unknown("(display-mode: 1%)");

  test(() => {
    let booleanContext = window.matchMedia("(display-mode)");
    assert_true(booleanContext.matches);
  }, "Check that display-mode evaluates to true in the boolean context");
</script>