dfcreative/mucss

/**
 * Parse element’s borders
 *
 * @module mucss/borders
 */

var Rect = require('./rect');
var parse = require('./parse-value');

/**
 * Return border widths of an element
 */
module.exports = function(el){
    if (el === window) return Rect();

    if (!(el instanceof Element)) throw Error('Argument is not an element');

    var style = window.getComputedStyle(el);

    return Rect(
        parse(style.borderLeftWidth),
        parse(style.borderTopWidth),
        parse(style.borderRightWidth),
        parse(style.borderBottomWidth)
    );
};