predict · objects
A spread, and a change to something inside it.
Answer before anything runs. Then the machine runs it, and you can step through what it did.
const defaults = { retries: 1, hosts: ["a"] };
const config = { ...defaults };
config.retries = 5;
config.hosts.push("b");
const retries = defaults.retries;
const hosts = defaults.hosts.length;