keep properties private in a closure with a getter/setter proxy

store.js

'use strict';

// keeping things private
let store = (() => {
	let debug = true;
	let state = {
		isLoggedIn: false,
		user: {}
	};

	// Map each of the properties from the state object to getters
	// and setters that we'll return.
	let proxy = Object.keys(state).reduce((hash, key) => {
		return Object.defineProperty(hash, key, {
			get() {
				return state[key];
			},
			set(newVal) {
				debug && console.log(`state changed triggered: setting ${key} to ${newVal}`);
				state[key] = newVal;
			},
			enumerable: true
		});
	}, {});

	return proxy;

})();

console.log(store.isLoggedIn);
store.isLoggedIn = true;
console.log(store.isLoggedIn);
// delete store.isLoggedIn; // <-- throws