css_visitors.NestingSelector() — svelte Function Reference

Source Code

packages/svelte/src/compiler/phases/2-analyze/css/css-analyze.js lines 287–315

	NestingSelector(node, context) {
		const rule = /** @type {AST.CSS.Rule} */ (context.state.rule);
		const parent_rule = rule.metadata.parent_rule;

		if (!parent_rule) {
			// https://developer.mozilla.org/en-US/docs/Web/CSS/Nesting_selector#using_outside_nested_rule
			const children = rule.prelude.children;
			const selectors = children[0].children[0].selectors;
			if (
				children.length > 1 ||
				selectors.length > 1 ||
				selectors[0].type !== 'PseudoClassSelector' ||
				selectors[0].name !== 'global' ||
				selectors[0].args?.children[0]?.children[0].selectors[0] !== node
			) {
				e.css_nesting_selector_invalid_placement(node);
			}
		} else if (
			// :global { &.foo { ... } } is invalid
			parent_rule.metadata.is_global_block &&
			!parent_rule.metadata.parent_rule &&
			parent_rule.prelude.children[0].children.length === 1 &&
			parent_rule.prelude.children[0].children[0].selectors.length === 1
		) {
			e.css_global_block_invalid_modifier_start(node);
		}

		context.next();
	}