+
−<!-- quirks mode -->
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−<title>CSS Values and Units Test: CSS inline if() function supports() in quirks mode</title>
+
−<meta name="assert" content="Test inline if() function with supports() query in quirks mode">
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−<link rel="help" href="https://drafts.csswg.org/css-values-5/#if-notation">
+
−<script src="/resources/testharness.js"></script>
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−<script src="/resources/testharnessreport.js"></script>
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−<style>
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−    div {
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−      color: red;
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−      --x: if(supports(width: 30): true_value; else: false_value;)
+
−    }
+
−</style>
+
−<div id="if">test</div>
+
−<script>
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−  setup({ single_test: true });
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−  var elem = document.getElementById("if");
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−  let val = window.getComputedStyle(elem).getPropertyValue("--x");
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−  assert_equals(val, "true_value");
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−  done();
+
−</script>