css/css-ui/appearance-initial-value-001.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Basic User Interface Test: appearance and -webkit-appearance</title>
<link rel="help" href="https://drafts.csswg.org/css-ui-4/#appearance-switching">
<meta name="assert" content="The appearance and -webkit-appearance properties are supported.">
<meta name="assert" content="Initial value is none.">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
 #appearance { appearance: button; }
 #-webkit-appearance { -webkit-appearance: button; }
</style>
<div id="appearance"></div>
<div id="-webkit-appearance"></div>
<div id="initial"></div>
<script>
for (const prop of ['appearance', '-webkit-appearance']) {
	test(() => {
		const actual = getComputedStyle(document.getElementById(prop)).getPropertyValue(prop);
		assert_equals(actual, 'button');
	}, `support for ${prop}`);

	test(() => {
		const actual = getComputedStyle(document.getElementById('initial')).getPropertyValue(prop);
		assert_equals(actual, 'none');
	}, `initial value for ${prop}`);
}
</script>