stylelint/lib/utils/isStandardSyntaxTypeSelector.js

A mighty, modern CSS linter.

/* @flow */
'use strict';

/**
 * Check whether a type selector is standard
 *
 * @param {Node} postcss-selector-parser node (of type tag)
 * @return {boolean} If `true`, the type selector is standard
 */

const _ = require('lodash');
const keywordSets = require('../reference/keywordSets');

module.exports = function(node /*: Object*/) /*: boolean*/ {
	// postcss-selector-parser includes the arguments to nth-child() functions
	// as "tags", so we need to ignore them ourselves.
	// The fake-tag's "parent" is actually a selector node, whose parent
	// should be the :nth-child pseudo node.
	const _node$parent$parent = node.parent.parent;
	const parentType = _node$parent$parent.type;
	const parentValue = _node$parent$parent.value;

	if (parentValue) {
		const normalisedParentName = parentValue.toLowerCase().replace(/:+/, '');

		if (
			parentType === 'pseudo' &&
			(keywordSets.aNPlusBNotationPseudoClasses.has(normalisedParentName) ||
				keywordSets.linguisticPseudoClasses.has(normalisedParentName))
		) {
			return false;
		}
	}

	// &-bar is a nesting selector combined with a suffix
	if (node.prev() && node.prev().type === 'nesting') {
		return false;
	}

	if (node.value[0] === '%') {
		return false;
	}

	// Reference combinators like `/deep/`
	if (_.startsWith(node.value, '/') && _.endsWith(node.value, '/')) {
		return false;
	}

	return true;
};