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

wpt / css / css-backgrounds / parsing / background-position-x-valid.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'] = "center" should set the property value	PASS
e.style['background-position-x'] = "left" should set the property value	PASS
e.style['background-position-x'] = "right" should set the property value	PASS
e.style['background-position-x'] = "x-start" should set the property value	FAIL	assert_not_equals: property should be set got disallowed value ""
e.style['background-position-x'] = "x-end" should set the property value	FAIL	assert_not_equals: property should be set got disallowed value ""
e.style['background-position-x'] = "-20%" should set the property value	PASS
e.style['background-position-x'] = "10px" should set the property value	PASS
e.style['background-position-x'] = "0.5em" should set the property value	PASS
e.style['background-position-x'] = "calc(10px - 0.5em)" should set the property value	PASS
e.style['background-position-x'] = "left -20%" should set the property value	PASS
e.style['background-position-x'] = "right 10px" should set the property value	PASS
e.style['background-position-x'] = "-20%, 10px" should set the property value	PASS
e.style['background-position-x'] = "center, left, right" should set the property value	PASS
e.style['background-position-x'] = "0.5em, x-start, x-end" should set the property value	FAIL	assert_not_equals: property should be set got disallowed value ""
e.style['background-position-x'] = "calc(10px - 0.5em), left -20%, right 10px" should set the property value	PASS

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

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>CSS Backgrounds and Borders Module Level 4: parsing background-position-x with valid 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 the full 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_valid_value("background-position-x", "center");
test_valid_value("background-position-x", "left");
test_valid_value("background-position-x", "right");
test_valid_value("background-position-x", "x-start");
test_valid_value("background-position-x", "x-end");
test_valid_value("background-position-x", "-20%");
test_valid_value("background-position-x", "10px");
test_valid_value("background-position-x", "0.5em");
test_valid_value("background-position-x", "calc(10px - 0.5em)", "calc(-0.5em + 10px)");
test_valid_value("background-position-x", "left -20%");
test_valid_value("background-position-x", "right 10px");
test_valid_value("background-position-x", "-20%, 10px");
test_valid_value("background-position-x", "center, left, right");
test_valid_value("background-position-x", "0.5em, x-start, x-end");
test_valid_value("background-position-x", "calc(10px - 0.5em), left -20%, right 10px", "calc(-0.5em + 10px), left -20%, right 10px");
</script>
</body>
</html>