title: runPromisesInSeries tags: function,promise,intermediate

Runs an array of promises in series.

Use Array.prototype.reduce() to create a promise chain, where each promise returns the next promise when resolved.

type PromisableFunc = (...args: any[]) => Promise<any>;
const runPromisesInSeries = (ps: PromisableFunc[]) =>
  ps.reduce((p, next) => p.then(next), Promise.resolve());

const delay = (d) => new Promise((r) => setTimeout(r, d));
runPromisesInSeries([() => delay(1000), () => delay(2000)]); // Executes each promise sequentially, taking a total of 3 seconds to complete