closest.js 864 字节
var DOCUMENT_NODE_TYPE = 9;

/**
 * A polyfill for Element.matches()
 */
if (typeof Element !== 'undefined' && !Element.prototype.matches) {
    var proto = Element.prototype;

    proto.matches = proto.matchesSelector ||
                    proto.mozMatchesSelector ||
                    proto.msMatchesSelector ||
                    proto.oMatchesSelector ||
                    proto.webkitMatchesSelector;
}

/**
 * Finds the closest parent that matches a selector.
 *
 * @param {Element} element
 * @param {String} selector
 * @return {Function}
 */
function closest (element, selector) {
    while (element && element.nodeType !== DOCUMENT_NODE_TYPE) {
        if (typeof element.matches === 'function' &&
            element.matches(selector)) {
          return element;
        }
        element = element.parentNode;
    }
}

module.exports = closest;