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.


const runPromisesInSeries = ps => 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