Blitz - WPT: background-size-computed.html

wpt / css / css-backgrounds / parsing / background-size-computed.html

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

Subtest	Status	Message
Property background-size value '1px'	PASS
Property background-size value '1px auto'	PASS
Property background-size value '2% 3%'	PASS
Property background-size value 'auto'	PASS
Property background-size value 'auto auto'	PASS
Property background-size value 'auto 4%'	PASS
Property background-size value 'contain'	PASS
Property background-size value 'cover'	PASS
Property background-size value 'calc(10px + 0.5em) calc(10px - 0.5em)'	PASS
Property background-size value 'calc(10px - 0.5em) calc(10px + 0.5em)'	PASS
Property background-size value 'auto 1px, 2% 3%, contain'	PASS
Property background-size value 'auto' multiple base values	PASS
Property background-size value 'auto, auto' multiple base values	PASS
Property background-size value 'auto, auto, auto' multiple base values	PASS
Property background-size value 'auto, 100%' multiple base values	PASS
Property background-size value '100%' multiple base values	PASS

Enable JavaScript in test iframe

/css/css-backgrounds/parsing/background-size-computed.html

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>CSS Backgrounds and Borders: getComputedStyle().backgroundSize</title>
<link rel="help" href="https://drafts.csswg.org/css-backgrounds/#background-size">
<meta name="assert" content="background-size computed value is a list, each item a pair of sizes (one per axis) each represented as either a keyword or a computed length-percentage value.">
<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-size", "1px", "1px auto");
test_computed_value("background-size", "1px auto", "1px auto");
test_computed_value("background-size", "2% 3%");
test_computed_value("background-size", "auto");
test_computed_value("background-size", "auto auto", "auto");
test_computed_value("background-size", "auto 4%");
test_computed_value("background-size", "contain");
test_computed_value("background-size", "cover");
test_computed_value("background-size", "calc(10px + 0.5em) calc(10px - 0.5em)", "30px 0px");
test_computed_value("background-size", "calc(10px - 0.5em) calc(10px + 0.5em)", "0px 30px");
test_computed_value("background-size", "auto 1px, 2% 3%, contain");

document.getElementById("target").style['background-image'] = "none, none";
test_computed_value("background-size", "auto", "auto", "multiple base values");
test_computed_value("background-size", "auto, auto", "auto, auto", "multiple base values");
test_computed_value("background-size", "auto, auto, auto", "auto, auto, auto", "multiple base values");
test_computed_value("background-size", "auto, 100%", "auto, 100% auto", "multiple base values");
test_computed_value("background-size", "100%", "100% auto", "multiple base values");
</script>
</body>
</html>