Duplicated logic in Observables

duplicated-logic.ts

import { from } from "rxjs";
import { filter, reduce } from "rxjs/operators";

const number$ = from([null, 2, 1, undefined, 5, false, 6, 7]);

// Adding numbers
number$
  .pipe(
    filter<number>(Boolean),
    reduce((acc, curr) => acc + curr)
  )
  .subscribe(n => console.log(`Total: ${n}`));

// Emit even numbers
number$
  .pipe(
    filter<number>(Boolean),
    filter(n => n % 2 === 0)
  )
  .subscribe(console.log);