stylelint/lib/rules/selector-max-compound-selectors/index.cjs

A mighty CSS linter that helps you avoid errors and enforce conventions.

// NOTICE: This file is generated by Rollup. To modify it,
// please instead edit the ESM counterpart and rebuild with Rollup (npm run build).
'use strict';

const selectorParser = require('postcss-selector-parser');
const validateTypes = require('../../utils/validateTypes.cjs');
const flattenNestedSelectorsForRule = require('../../utils/flattenNestedSelectorsForRule.cjs');
const getStrippedSelectorSource = require('../../utils/getStrippedSelectorSource.cjs');
const isContextFunctionalPseudoClass = require('../../utils/isContextFunctionalPseudoClass.cjs');
const isNonNegativeInteger = require('../../utils/isNonNegativeInteger.cjs');
const isStandardSyntaxRule = require('../../utils/isStandardSyntaxRule.cjs');
const optionsMatches = require('../../utils/optionsMatches.cjs');
const pluralize = require('../../utils/pluralize.cjs');
const report = require('../../utils/report.cjs');
const ruleMessages = require('../../utils/ruleMessages.cjs');
const validateOptions = require('../../utils/validateOptions.cjs');

const { isCombinator, isPseudo, isRoot, isSelector } = selectorParser;

const ruleName = 'selector-max-compound-selectors';

const messages = ruleMessages(ruleName, {
	expected: (selector, /** @type {number} */ max) =>
		`Expected "${selector}" to have no more than ${max} compound ${pluralize('selector', max)}`,
});

const meta = {
	url: 'https://stylelint.io/user-guide/rules/selector-max-compound-selectors',
};

/** @type {import('stylelint').CoreRules[ruleName]} */
const rule = (primary, secondaryOptions) => {
	return (root, result) => {
		const validOptions = validateOptions(
			result,
			ruleName,
			{
				actual: primary,
				possible: isNonNegativeInteger,
			},
			{
				actual: secondaryOptions,
				possible: {
					ignoreSelectors: [validateTypes.isString, validateTypes.isRegExp],
				},
				optional: true,
			},
		);

		if (!validOptions) {
			return;
		}

		/**
		 * @param {import('postcss-selector-parser').Node} selectorNode
		 * @returns {boolean}
		 */
		function isSelectorIgnored(selectorNode) {
			const selector = isPseudo(selectorNode) ? selectorNode.value : selectorNode.toString();

			return optionsMatches(secondaryOptions, 'ignoreSelectors', selector);
		}

		/**
		 * @param {import('postcss-selector-parser').Selector} resolvedSelectorNode
		 * @param {import('postcss-selector-parser').Selector} selectorNode
		 * @param {import('postcss').Rule} ruleNode
		 */
		function checkSelector(resolvedSelectorNode, selectorNode, ruleNode) {
			/** @type {import('postcss-selector-parser').Node[]} */
			const filteredChildNodes = [];

			resolvedSelectorNode.each((childNode) => {
				if (!isSelectorIgnored(childNode)) {
					filteredChildNodes.push(childNode);
				}
			});

			if (isRoot(selectorNode) || isPseudo(selectorNode)) return;

			// Normalize selector nodes and count combinators
			const combinatorCount = filteredChildNodes.reduce((count, node, i, nodes) => {
				// Not count a node except a combinator
				if (!isCombinator(node)) return count;

				// Not count a combinator at the edge
				if (i === 0 || i === nodes.length - 1) return count;

				// Not count a consecutive combinator
				if (isCombinator(nodes[i + 1])) return count;

				return count + 1;
			}, 0);

			const compoundCount = combinatorCount + 1;

			if (compoundCount > primary) {
				const { index, endIndex, selector: selectorStr } = getStrippedSelectorSource(selectorNode);

				report({
					ruleName,
					result,
					node: ruleNode,
					message: messages.expected,
					messageArgs: [selectorStr, primary],
					index,
					endIndex,
				});
			}
		}

		root.walkRules((ruleNode) => {
			if (!isStandardSyntaxRule(ruleNode)) return;

			flattenNestedSelectorsForRule(ruleNode, result).forEach(({ selector, resolvedSelectors }) => {
				resolvedSelectors.walk((childSelector) => {
					if (!isSelector(childSelector)) return;

					if (
						isRoot(childSelector.parent) ||
						isContextFunctionalPseudoClass(childSelector.parent)
					) {
						checkSelector(childSelector, selector, ruleNode);
					}
				});
			});
		});
	};
};

rule.ruleName = ruleName;
rule.messages = messages;
rule.meta = meta;

module.exports = rule;