/** Convert a value to CSS unit */
export function convertToUnit(str: string | number | null | undefined, unit = 'px'): string | undefined {
	if (str === undefined || str === null || str === '') {
		return undefined;
	} else if (isNaN(+str)) { // If NaN, it's a string with unit, use as is
		return String(str);
	} else {
		return `${Number(str)}${unit}`;
	}
}