Print message array every 5000 ms or if the buffer reach 5 items

app.component.ts

export class AppComponent implements OnInit {
  messageBuffer$ = new Subject<string>();

  msgCount = 0;
  ngOnInit(): void {
    this.messageBuffer$.pipe(
      bufferTime(5000, null, 5),
      filter(buffer => buffer.length > 0),
    ).subscribe(console.log);
  }

  sendSomeMessage() {
    this.messageBuffer.next(`Message ${++this.msgCount}`)
  }
}