Friendlier object definition

define.js

const define = (object, ...pairs) =>
  (Array.isArray(pairs[0]) ? pairs : [pairs]).reduce((accumulator, pair) => {
    const [ key, value ] = pair;
    return Object.defineProperty(accumulator, key, { value, enumerable: true }); 
  }, object);

Example:

const obj = {};

// single property
define(obj, "foo", "bar");

// tuples
define(obj, ["a", 1], ["b", 2]);

console.log(obj); // => {foo: "bar", a: 1, b: 2}