custom-property-rule-ambiguity.html

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This WPT test may be referenced by the following Test IDs:
- /css/css-syntax/custom-property-rule-ambiguity.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<title>CSS Syntax: Rules that look like custom properties</title>

<link rel="help" href="https://drafts.csswg.org/css-syntax/#consume-qualified-rule">

<script src="/resources/testharness.js"></script>

<script src="/resources/testharnessreport.js"></script>

<style id=stylesheet1>

  .a { }

  --x:hover { } /* Ambiguous "rule" */

  .b { }

</style>

<script>

  test(() => {

    let rules = stylesheet1.sheet.rules;

    assert_equals(rules.length, 2);

    assert_equals(rules[0].selectorText, '.a');

    assert_equals(rules[1].selectorText, '.b');

  }, 'Rule that looks like a custom property declaration is ignored');

</script>

<!-- https://github.com/w3c/csswg-drafts/issues/9336 -->

<style id=stylesheet2>

  .a { }

  --x:hover { ] } /* Ambiguous "rule" */

  .b { }

</style>

<script>

  test(() => {

    let rules = stylesheet2.sheet.rules;

    assert_equals(rules.length, 2);

    assert_equals(rules[0].selectorText, '.a');

    assert_equals(rules[1].selectorText, '.b');

  }, 'Rule that looks like an invalid custom property declaration is ignored');

</script>

<style id=stylesheet3>

  div {

    .a { }

    --x:hover { }

    .b { }

</style>

<script>

  test(() => {

    let rules = stylesheet3.sheet.rules;

    assert_equals(rules.length, 1);

    assert_equals(rules[0].selectorText, 'div');

    let div = rules[0];

    let x = div.style.getPropertyValue('--x');

    assert_equals(x.trim(), 'hover { }\n    .b { }');

    let childRules = div.cssRules;

    assert_equals(childRules.length, 1);

    assert_equals(childRules[0].selectorText, '& .a');

  }, 'Nested rule that looks like a custom property declaration');

</script>

<!-- https://github.com/w3c/csswg-drafts/issues/9336 -->

<style id=stylesheet4>

  div {

    .a { }

    --x:hover { ] }

    .b { }

</style>

<script>

  test(() => {

    let rules = stylesheet4.sheet.rules;

    assert_equals(rules.length, 1);

    assert_equals(rules[0].selectorText, 'div');

    let div = rules[0];

    // There is no valid --x declaration, because mismatched ] is not allowed

    // in custom properties.

    let x = div.style.getPropertyValue('--x');

    assert_equals(x, '');

    // We should also not have restarted parsing as a nested style rule,

    // and instead we should have "consumed the remnants of a bad declaration",

    // which skips to the next semicolon (or end-of-block).

    // So in other words, there should be no nested '.b.' child rule here.

    let childRules = div.cssRules;

    assert_equals(childRules.length, 1);

    assert_equals(childRules[0].selectorText, '& .a');

  }, 'Nested rule that looks like an invalid custom property declaration');

</script>