GitHub - BYK/superset: A library that provides the missing Set methods for ES6 such as map and filter.

A library for ES6 that extends the built-in Set class to implement the missing fundamental methods such as map(), filter() and reduce() in addition to basic set methods such as union() and isSubsetOf().

"use strict";

const SuperSet = require("superset");
const numbers = new SuperSet([1, 2, 3, 4, 5]);
const evenNumbers = numbers.filter(num => num % 2 === 0);  // SuperSet { 2, 4 }

evenNumbers.isSubsetOf(numbers);  // true

numbers.diff(evenNumbers);  // SuperSet { 1, 3, 5 }

You can check out the docs or refer to the Array methods on MDN for further information. The code is also documented using JSDoc.