Angular - When to handle errors in Observable's subscription

Question

I have found myself working with code from themes written in latest Angular versions and searching the web, and I have found that the most part of devs don't handle the subscription error.

My question is: When do I have to handle the error in an Observable subscription?

Without error handling:

    this.myService.observable$.subscribe(
        (data) => {
            // do stuff with data
        }
    );

With error handling:

    this.myService.observable$.subscribe(
        (data) => {
            // do stuff with data
        },
        err => {
            // do stuff with error
        }
    );

I mostly find the first version, but...

Isn't an issue not to handle the errors of a subscription?

Doesn't this make the code less solid, testable and more prone to fail?

Answer 1

why is error handling important click Me

Now Lets see Why error handling is necessary in Observables..

Example:

this.service.send(this.shareData).subscribe(() => {

      // Here you are sure that the send has shared the data sucessFully

    }, (error) => {

      /* Now If you want to handle errors Like Front End Errors and Log this
         In your backEnd DB So solve it and fix it */

      /* Example below check error type is It from frontEnd and log error through Api */

      if(error.type !== 'API') {
        this.logService.log({
          Level: 2,
          Message: 'Failed to setFromDB',
        });
      }
    });