istarkov

// promise
const sleep = (timeout, v) => new Promise(r => setTimeout(() => r(v), timeout));
// series to call
const series = [() => sleep(1000, 1), () => sleep(1000, 2), () => sleep(1000, 3)];

// serialize
const r = series
  .reduce(
    (m, p) => m.then(v => Promise.all([...v, p()])),
    Promise.resolve([])