javascript - RxJS. Combine observables that emit less then 1 second apart

Question

There are two observables that may be emiting together or separately: stream1 and stream2. I need my subscription to fire only if stream2 fires less then 1 second after stream1 does.
Any way to achieve that with RxJS?

Answer 1

You can use a timestamp and withLatestFrom to decide which values to emit Here I just filter such that only values that meet your condition pass through.

stream2.pipe(
  timestamp(),
  withLatestFrom(stream1.pipe(
    timestamp(),
    startWith({timestamp: 0, value: null})
  )),
  filter(([s2, s1]) => s2.timestamp - s1.timestamp < 1000),
  map(([s2, s1]) => ({
    stream1: s1.value,
    stream2: s2.value
  }))
);