shepelevstas

// correct object cloning
function clone(obj, fields) {
	if (null == obj || "object" != typeof obj) return obj;
	if (obj.constructor == File && obj.size)
		return obj
	var copy = obj.constructor();

	if (fields){
		for (let i of fields)
			if (obj.hasOwnProperty(i))

shepelevstas

function deepEq( x, y, propertyList, pred ) {
  if ( x === y ) return true;
    // if both x and y are null or undefined and exactly the same

  if ( ! ( x instanceof Object ) || ! ( y instanceof Object ) ) return false;
    // if they are not strictly equal, they both need to be Objects

  if ( x.constructor !== y.constructor ) return false;
    // they must have the exact same prototype chain, the closest we can do is
    // test there constructor.