export const mount = (reference) => { if (!reference.nextElementSibling) { return } const target = reference.nextElementSibling let placement = reference.getBoundingClientRect().left > innerWidth / 2 ? 'left' : 'right' if ( reference.getBoundingClientRect().left + target.getBoundingClientRect().width > innerWidth ) { placement = 'left' } if ( reference.getBoundingClientRect().left - target.getBoundingClientRect().width < 0 ) { placement = 'right' } target.dataset.placement = placement }