object-swap-arrow-func-comma-operator.js

// I'm using an IIFE since currently chrome console doesn't allow you to specify let statements in sloppy mode
(function test() {
    "use strict";
    let obj = { key1: "value1", key2: "value2" };
    let swapped = Object
        .keys(obj)
        .reduce((res, key) => (res[obj[key]] = key, res), {});
    console.log(swapped);
})();