superSet.js

const superSet = arr => {
	var result = [];
	result.push([])
  	arr.forEach(val => {
		let length = result.length;
		let i = 0;
    		while(i < length){
			let newAr = result[i].slice(0);
			newAr.push(val);
			result.push(newAr);
			i++;
		}
  	});
  	return result;
}

const setArr = [1,2,3]
const superSetArr = superSet(setArr); //[[],[1],[2],[1,2],[3],[1,3],[2,3],[1,2,3]]