// RxJS v6+
import { timer } from 'rxjs';
import { windowTime, tap, mergeAll } from 'rxjs/operators';
//emit immediately then every 1s
const source = timer(0, 1000);
const example = source.pipe(
//start new window every 3s
windowTime(3000),
tap(_ => console.log('NEW WINDOW!'))
);
const subscribeTwo = example
.pipe(
//window emits nested observable
mergeAll()
/*
output:
"NEW WINDOW!"
0
1
2
"NEW WINDOW!"
3
4
5
*/
)
.subscribe(val => console.log(val));