chromium/third_party/blink/web_tests/external/wpt/css/selectors/focus-visible-001.html

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8" />
  <title>CSS Test (Selectors): Keyboard focus enables :focus-visible</title>
  <link rel="author" title="Rob Dodson" href="[email protected]" />
  <link rel="help" href="https://drafts.csswg.org/selectors-4/#the-focus-visible-pseudo" />
  <script src="/resources/testharness.js"></script>
  <script src="/resources/testharnessreport.js"></script>
  <script src="/resources/testdriver.js"></script>
  <script src="/resources/testdriver-actions.js"></script>
  <script src="/resources/testdriver-vendor.js"></script>
  <style>
    @supports not selector(:focus-visible) {
      :focus {
        outline: red solid 5px;
        background-color: red;
      }
    }

    :focus-visible {
      outline: green solid 5px;
    }

    :focus:not(:focus-visible) {
      outline: 0;
      background-color: red;
    }
  </style>
</head>
<body>
  This test checks that using the Tab key to navigate focus to an element triggers <code>:focus-visible</code> matching.
  <ol id="instructions">
    <li>If the user-agent does not claim to support the <code>:focus-visible</code> pseudo-class then SKIP this test.</li>
    <li>Use the TAB key on the keyboard to focus the element below that says "Focus me."</li>
    <li>If the element has a red background, then the test result is FAILURE. If the element has a green outline, then the test result is SUCCESS.</li>
  </ol>
  <br>
  <div id="el" tabindex="0">Focus me.</div>
  <script>
    async_test(function(t) {
      el.addEventListener("focus", t.step_func_done(function() {
        assert_equals(getComputedStyle(el).outlineColor, "rgb(0, 128, 0)", `outlineColor for ${el.tagName}#${el.id} should be green`);
        assert_not_equals(getComputedStyle(el).backgroundColor, "rgb(255, 0, 0)", `backgroundColor for ${el.tagName}#${el.id} should NOT be red`);

        let focusVisiblePseudoAll = document.querySelectorAll(':focus-visible');
        assert_equals(focusVisiblePseudoAll.length, 1, "Only 1 element matches ':focus-visible'");
        let focusVisiblePseudo = document.querySelector(':focus-visible');
        assert_equals(el, focusVisiblePseudo, "${el.tagName}#${el.id} matches ':focus-visible'");
      }));
      const tab_key = '\ue004';
      test_driver.send_keys(el, tab_key)
        .catch(e => t.step_func(() => assert_unreached("Actions sequence failed " + e)));
    }, "Keyboard focus should match :focus-visible");
  </script>
</body>
</html>