src/utils/geometry.js
function getBordersSize(styles, ...positions) {
    return positions.reduce((size, position) => {
        const value = styles['border-' + position + '-width'];

        return size + toFloat(value);
    }, 0);
}
function getBordersSize(styles, ...positions) {
    return positions.reduce((size, position) => {
        const value = styles['border-' + position + '-width'];

        return size + toFloat(value);
    }, 0);
}
function getBordersSize ( styles , ... positions ) { return positions . reduce ( ( size , position ) => { const value = styles [ 'border-' + position + '-width' ] ; return size + toFloat ( value ) ; } , 0 ) ; }
Extracts borders size from provided styles.

@param {CSSStyleDeclaration} styles
@param {...string} positions - Borders positions (top, right, ...)
@returns {number}
Extracts borders size from provided styles .