css/selectors/webkit-pseudo-element.html

<!DOCTYPE html>
<title>WebKit-prefixed pseudo-elements</title>
<link rel="author" title="Xidorn Quan" href="https://www.upsuper.org">
<link rel="author" title="Mozilla" href="https://www.mozilla.org">
<link rel="help" href="https://drafts.csswg.org/selectors-4/#compat">
<meta name="assert" content="WebKit-prefixed pseudo-elements should always be valid">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style id="style">
#test {
  color: rgb(255, 0, 0);
}
span::-webkit-something-invalid, #test, ::-WeBkIt-sOmEtHiNg-NoNeXiSt123, ::-webkit-\ escaped {
  color: rgb(0, 255, 0);
}
::-webkitfoo, #test {
  color: rgb(255, 0, 0);
}
</style>
<body>
<div id="test"></div>
<script>
  test(() => {
    let elem = document.getElementById("test");
    assert_equals(getComputedStyle(elem).color, "rgb(0, 255, 0)");
  }, "rules include webkit-prefixed pseudo-element should be cascaded");

  test(() => {
    let sheet = document.getElementById("style").sheet;
    assert_equals(sheet.cssRules[1].selectorText,
                  "span::-webkit-something-invalid, " +
                  "#test, ::-webkit-something-nonexist123, " +
                  "::-webkit-\\ escaped");
  }, "webkit-prefixed pseudo-element selectors should be accessible from CSSOM");

  test(() => {
    document.querySelector("span::-webkit-something-invalid");
    document.querySelectorAll("span::-webkit-something-invalid");
  }, "qS and qSA shouldn't throw exception");

  test(() => {
    let sheet = document.getElementById("style").sheet;
    assert_equals(sheet.cssRules.length, 2);
    assert_throws_dom("SyntaxError", () => document.querySelector("span::-webkitfoo"));
    assert_throws_dom("SyntaxError", () => document.querySelectorAll("span::-webkitfoo"));
  }, "webkit-prefix without dash is invalid");
</script>
</body>