<!
doctype html>
<
title>CSS Selectors parsing</
title>
<
link rel=
"author" title=
"Adam Argyle" href=
"mailto:argyle@google.com">
<
link rel=
"author" title=
"Tab Atkins-Bittner" href=
"https://tabatkins.com/contact/">
<
link rel=
"help" href=
"https://drafts.csswg.org/css-nesting-1/">
<
script src=
"/resources/testharness.js"></
script>
<
script src=
"/resources/testharnessreport.js"></
script>
<
style id=
"test-sheet"></
style>
<
script>
let [ss] = document.styleSheets
function resetStylesheet() {
while (ss.rules.length)
ss.removeRule(0)
}
function testNestedSelector(sel, {expected=sel, parent=
".foo"}={}) {
resetStylesheet();
const ruleText = `${parent} { ${sel} { color: green; }}`
test(()=>{
ss.insertRule(ruleText);
assert_equals(ss.rules.length, 1,
"Outer rule should exist.");
const rule = ss.rules[0];
assert_equals(rule.cssRules.length, 1,
"Inner rule should exist.");
const innerRule = rule.cssRules[0];
assert_equals(innerRule.selectorText, expected, `Inner rule
's selector should be "${expected}".`);
}, ruleText);
}
function testInvalidNestingSelector(sel, {parent=
".foo"}={}) {
resetStylesheet();
const ruleText = `${parent} { ${sel} { color: green; }}`
test(()=>{
ss.insertRule(ruleText);
assert_equals(ss.rules.length, 1,
"Outer rule should exist.");
const rule = ss.rules[0];
assert_equals(rule.cssRules.length, 0,
"Inner rule should not exist.");
},
"INVALID: " + ruleText);
}
// basic usage
testNestedSelector(
"&");
testNestedSelector(
"&.bar");
testNestedSelector(
"& .bar");
testNestedSelector(
"& > .bar");
// relative selector
testNestedSelector(
"> .bar", {expected:
"& > .bar"});
testNestedSelector(
"> & .bar", {expected:
"& > & .bar"});
testNestedSelector(
"+ .bar &", {expected:
"& + .bar &"});
testNestedSelector(
"+ .bar, .foo, > .baz", {expected:
"& + .bar, & .foo, & > .baz"});
// implicit relative (and not)
testNestedSelector(
".foo", {expected:
"& .foo"});
testNestedSelector(
".test > & .bar");
testNestedSelector(
".foo, .foo &", {expected:
"& .foo, .foo &"});
testNestedSelector(
".foo, .bar", {expected:
"& .foo, & .bar"});
testNestedSelector(
":is(.bar, .baz)", {expected:
"& :is(.bar, .baz)"});
testNestedSelector(
"&:is(.bar, .baz)");
testNestedSelector(
":is(.bar, &.baz)");
testNestedSelector(
"&:is(.bar, &.baz)");
// Mixing nesting selector with other simple selectors
testNestedSelector(
"div&");
testInvalidNestingSelector(
"&div"); // type selector must be first
testNestedSelector(
".class&");
testNestedSelector(
"&.class");
testNestedSelector(
"[attr]&");
testNestedSelector(
"&[attr]");
testNestedSelector(
"#id&");
testNestedSelector(
"&#id");
testNestedSelector(
":hover&");
testNestedSelector(
"&:hover");
testNestedSelector(
":is(div)&");
testNestedSelector(
"&:is(div)");
// Multiple nesting selectors
testNestedSelector(
"& .bar & .baz & .qux");
testNestedSelector(
"&&");
// Selector list in inner rule
testNestedSelector(
"& > section, & > article");
// Selector list in both inner and outer rule.
testNestedSelector(
"& + .baz, &.qux", {parent:
".foo, .bar"});
</
script>
