RxJS: Observable.never() keeps like subscription

Question

I\'m using rxjs 5.5.6.

I\'ve created this code in order to show the behavior:

Observable.of(1, 2)
    .do(a => {
        console.log(a);
        let d         


        

Answer 1

Yes all the explanation by @frido is correct. With that answer I would like to add:

If you want to capture any error occuring in any particular Observable itself(say an HTTP request) then you need to handle it in that particular erroring Observable.

  let correct = Observable.of("correct")
  let inCorrect = Observable.throw('inCorect')

  let obs = [inCorrect, correct];
  let handledObs = obs.map(eachObs => {
    return eachObs.catch((e) => {
      console.log("Individual handler, Good Catch!");
      return Observable.of("I am tampered");
    })
  })

  forkJoin(...handledObs)
  .do(a => {
      console.log(a);
  })
  .catch(() => {
      console.log("error catched");
      return Observable.never();
  })
  .subscribe(data => {
    console.log(`data`, data)
  },(e) => {
      console.log(`error`, e)
  });

}

See an example here: https://stackblitz.com/edit/angular-7mmhn7?file=src/app/app.component.ts

---

EDIT

However when I look at your code, it looks to me that you are trying to log something and the returned data may not have a length property, even in that case you want to proceed with the stream. If this is true then you can add a simple try catch under do()

  from([1, 2])
  .do(a => {
      try {
        console.log(a);
        let d:string = null;
        let r = d.length;
      } catch(e) {
        console.log(`catched under do`, e)
      }
  })
  .catch(() => {
      console.log("error catched");
      return Observable.of('catched');
  })
  .subscribe(data => {
    console.log(`data`, data)
  },(e) => {
      console.log(`error`, e)
  });

Here is an example: https://stackblitz.com/edit/angular-bcrava?file=src/app/app.component.ts