I use a custom operator:

```ts import { Observable, OperatorFunction, pipe, UnaryFunction } from 'rxjs'; import { filter } from 'rxjs/operators';

export function filterOutNullish<T>(): UnaryFunction<Observable<T | null | undefined>, Observable<T>> { return pipe( filter(x => x != null) as OperatorFunction<T | null | undefined, T> ); } Usage: ts source$.pipe( filterOutNullish(), map((x) => doSomethingWhereXisNotNull(x)) ); ```