SOURCE

var test = {
  a: [1,2,3],
  b: 'sfasdf',
  c: {
    d: 1,
    e: true,
    f: ['a', 'b', 'c']
  },
  d: null,
}

function clone(val) {
  if(typeof val === 'number' || typeof val ==='string' || typeof val === 'boolean' || val === null) {
    return val;
  }
	if(Object.prototype.toString.call(val) === '[object Array]') {
    return val.map(v=>clone(v));
  }
  if(Object.prototype.toString.call(val) === "[object Object]") {
   return Object.keys(val).reduce((prev, key) => {
     prev[key] = clone(val[key]);
     return prev;
   }, {}); 
  }
}

const newTest = clone(test);
console.log(newTest);