rxjs Observable .map not executing

The map is never executed because it creates an observable that stays cold (no subscription). Add an empty subscribe() and it should work.

observable$.map(res => {
  console.warn ("IN MAP: " + JSON.stringify(res));
}).subscribe();

And another tip on rxjs debugging, if you want to peek into the value, you can always use the do operator (instead of your map).

observable$
  .do((v) => console.log('debug point: ', v)) // <-- this is the addition.
  .subscribe(...your original handlers go here ...)