<!doctype html>
<title>CSS Selectors parsing</title>
<link rel="author" title="Adam Argyle" href="mailto:[email protected]">
<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>