Blitz - WPT: background-position-x-invalid.html

wpt / css / css-backgrounds / parsing / background-position-x-invalid.html

Data from commit:
a50cb89 wpt: run reference-named files which are themselves tests (#836) (2026-09-03)

Subtest	Status	Message
e.style['background-position-x'] = "top" should not set the property value	PASS
e.style['background-position-x'] = "bottom" should not set the property value	PASS
e.style['background-position-x'] = "y-start" should not set the property value	PASS
e.style['background-position-x'] = "y-end" should not set the property value	PASS
e.style['background-position-x'] = "center 10px" should not set the property value	PASS
e.style['background-position-x'] = "20% left" should not set the property value	PASS
e.style['background-position-x'] = "right left" should not set the property value	PASS
e.style['background-position-x'] = "x-start center" should not set the property value	PASS
e.style['background-position-x'] = "left, center right" should not set the property value	PASS

Enable JavaScript in test iframe

/css/css-backgrounds/parsing/background-position-x-invalid.html

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>CSS Backgrounds and Borders Module Level 4: parsing background-position-x with invalid values</title>
<link rel="help" href="https://drafts.csswg.org/css-backgrounds-4/#propdef-background-position-x">
<meta name="assert" content="background-position-x supports only the grammar '[ center | [ left | right | x-start | x-end ]? <length-percentage>? ]#'.">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/css/support/parsing-testcommon.js"></script>
</head>
<body>
<script>
test_invalid_value("background-position-x", "top");
test_invalid_value("background-position-x", "bottom");
test_invalid_value("background-position-x", "y-start");
test_invalid_value("background-position-x", "y-end");
test_invalid_value("background-position-x", "center 10px");
test_invalid_value("background-position-x", "20% left");
test_invalid_value("background-position-x", "right left");
test_invalid_value("background-position-x", "x-start center");
test_invalid_value("background-position-x", "left, center right");
</script>
</body>
</html>