unique-id.js

/**
 * @file rule: unique-id
 * @author nighca<nighca@live.cn>
 */

module.exports = {

    name: 'unique-id',

    desc: 'Id should be unique in page.',

    lint: function (getCfg, document, reporter) {
        var idMap = {};

        document.querySelectorAll('[id]').forEach(function (element) {
            if (!getCfg(element)) {
                return;
            }

            if (element.id) {
                (idMap[element.id] = idMap[element.id] || []).push(element);
            }
        });

        var report = function (element) {
            reporter.warn(element.startIndex, '026', 'Id should be unique in page.');
        };

        Object.keys(idMap).forEach(function (id) {
            var elements = idMap[id];
            if (elements.length > 1) {
                elements.forEach(report);
            }
        });
    }

};