scancss/dist/calculators/calculateSpecificity/index.js

A robust CSS stylesheet statistics collector and analyzer

'use strict';

Object.defineProperty(exports, "__esModule", {
	value: true
});
exports.calculateSpecificity = calculateSpecificity;

var _cssPseudoClasses = require('../../constants/cssPseudoClasses');

var _cssPseudoElements = require('../../constants/cssPseudoElements');

var _reLeadingColons = require('../../constants/reLeadingColons');

/**
 * https://www.w3.org/TR/selectors-3/#specificity
 */

function calculateSpecificity(selector) {
	if (selector.type === 'id') {
		return [1, 0, 0];
	}

	if (selector.type === 'class' || selector.type === 'attribute') {
		return [0, 1, 0];
	}

	if (selector.type === 'tag') {
		return [0, 0, 1];
	}

	if (selector.type === 'pseudo') {
		const pseudoName = selector.value.replace(_reLeadingColons.reLeadingColons, '');

		if (_cssPseudoClasses.cssPseudoClasses.includes(pseudoName)) {
			/**
    * TODO: change calculation of `has`, `matches`, `not`, `nth-child`, `nth-last-child`
    * according to future spec https://drafts.csswg.org/selectors-4/#specificity-rules
    */
			if (['something', 'not'].includes(pseudoName)) {
				return [0, 0, 0];
			}

			return [0, 1, 0];
		}

		if (_cssPseudoElements.cssPseudoElements.includes(pseudoName)) {
			return [0, 0, 1];
		}
	}

	if (selector.type === 'universal') {
		return [0, 0, 0];
	}

	return [0, 0, 0];
}