Blitz - WPT: background-position-y-computed.html

wpt / css / css-backgrounds / parsing / background-position-y-computed.html

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

Subtest	Status	Message
Property background-position-y value 'center'	PASS
Property background-position-y value 'top'	PASS
Property background-position-y value 'bottom'	PASS
Property background-position-y value 'y-start'	FAIL	assert_true: 'y-start' is a supported value for background-position-y. expected true got false
Property background-position-y value 'y-end'	FAIL	assert_true: 'y-end' is a supported value for background-position-y. expected true got false
Property background-position-y value '-20%'	PASS
Property background-position-y value '10px'	PASS
Property background-position-y value '0.5em'	PASS
Property background-position-y value 'calc(10px - 0.5em)'	PASS
Property background-position-y value 'top -20%'	PASS
Property background-position-y value 'bottom -10px'	PASS
Property background-position-y value '-20%, 10px'	PASS
Property background-position-y value 'center, top, bottom'	PASS
Property background-position-y value '0.5em, y-start, y-end'	FAIL	assert_true: '0.5em, y-start, y-end' is a supported value for background-position-y. expected true got false
Property background-position-y value 'calc(10px - 0.5em), -20%, 10px'	PASS
Property background-position-y value 'calc(10px - 0.5em), top -20%, bottom 10px'	PASS
Property background-position-y value 'center' multiple base values	PASS
Property background-position-y value 'center, top' multiple base values	PASS
Property background-position-y value 'center, top, bottom' multiple base values	PASS

Enable JavaScript in test iframe

/css/css-backgrounds/parsing/background-position-y-computed.html

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>CSS Backgrounds and Borders Module Level 4: getComputedStyle().backgroundPositionY</title>
<link rel="help" href="https://drafts.csswg.org/css-backgrounds-4/#propdef-background-position-y">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/css/support/computed-testcommon.js"></script>
<style>
  #target {
    font-size: 40px;
  }
</style>
</head>
<body>
<div id="target"></div>
<script>
test_computed_value("background-position-y", "center", "50%");
test_computed_value("background-position-y", "top", "0%");
test_computed_value("background-position-y", "bottom", "100%");
test_computed_value("background-position-y", "y-start");
test_computed_value("background-position-y", "y-end");
test_computed_value("background-position-y", "-20%");
test_computed_value("background-position-y", "10px");
test_computed_value("background-position-y", "0.5em", "20px");
test_computed_value("background-position-y", "calc(10px - 0.5em)", "-10px");
test_computed_value("background-position-y", "top -20%", "-20%");
test_computed_value("background-position-y", "bottom -10px", "calc(100% + 10px)");
test_computed_value("background-position-y", "-20%, 10px");
test_computed_value("background-position-y", "center, top, bottom", "50%, 0%, 100%");
test_computed_value("background-position-y", "0.5em, y-start, y-end", "20px, 0%, 100%");
test_computed_value("background-position-y", "calc(10px - 0.5em), -20%, 10px", "-10px, -20%, 10px");
test_computed_value("background-position-y", "calc(10px - 0.5em), top -20%, bottom 10px", "-10px, -20%, calc(100% - 10px)");

document.getElementById("target").style['background-image'] = "none, none";
test_computed_value("background-position-y", "center", "50%", "multiple base values");
test_computed_value("background-position-y", "center, top", "50%, 0%", "multiple base values");
test_computed_value("background-position-y", "center, top, bottom", "50%, 0%, 100%", "multiple base values");
</script>
</body>
</html>