wpt / css / css-properties-values-api / at-property-optional-initial-value.html

Status: PASS | Duration: 51ms | Subtests: 1/1 | Open test on wpt.live | wpt.fyi

TestTest Source

/css/css-properties-values-api/at-property-optional-initial-value.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Properties and Values API: optional initial-value descriptor</title>
<link rel="help" href="https://drafts.css-houdini.org/css-properties-values-api/#initial-value-descriptor">
<link rel="help" href="https://github.com/w3c/csswg-drafts/issues/9078">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
@property --registered {
    syntax: '*';
    initial-value: ;
    inherits: false;
}
#target {
    --test-bg: var(--registered) green;
    --test-fallback: var(--registered, red);
    background-color: var(--test-bg, var(--test-fallback));
}
</style>
<div id="target"></div>
<script>
test(function() {
    const target = document.getElementById('target');
    const style = getComputedStyle(target);

    // When initial-value is omitted (empty space), the property should be registered
    // with a space character as the initial value, making var(--registered) green
    // evaluate to " green" which is a valid color value.
    assert_equals(style.backgroundColor, 'rgb(0, 128, 0)',
      'background-color should be green when @property has empty initial-value');
  }, '@property with empty initial-value should use space character');
</script>