Change DOM classes quickly.

changeClass.js

const changeClass = (target, firstCl, secondCl) => {
	// if first exist = add it
	// if both exist = change first to second
	// if both exist and first is * = overwrite with second
	if(firstCl) {
		if(!secondCl) {
			target.className += ` ${firstCl}`;
		} else {
			target.className = firstCl==="*"?
				secondCl:
				target.className.replace(new RegExp('\\s?'+firstCl), secondCl);
		}
	}
};