Errors within subscriptions

Documentation Related To Component:

https://rxjs-dev.firebaseapp.com/guide/subscription

Please check those that apply

• typo
• documentation doesn't exist
• documentation needs clarification
• error(s) in example
• needs example

Description Of The Issue

It's unclear to me what is meant to happen to happen if an error is thrown inside a subscription:

const logWithPrecision = i => console.log(i.toPrecision(2));
const logError = () => console.error(`Error in execution`);

const strings = interval(750).pipe(
  take(3),
  map(i => i.toString())
);
const numbers = interval(300).pipe(take(3));
merge(strings, numbers).subscribe(logWithPrecision, logError);


// 0.0
// 1.0
// ).subscribe((i: any) => console.log(i.toPrecision(2)));
//                                       ^
// TypeError: i.toPrecision is not a function
// ...

I might expect the error to be handled by the error handler, logError, as it would be with a promise:

new Promise(r => r('0')).then(logWithPrecision).catch(logError);
// Error in execution

I wouldn't expect the subscription to stop -- instead I would expect the final value from numbers to be logged, followed by a few more errors from the strings stream.

How are errors within a subscription meant to be handled? Is the subscription expected to stop, and should the complete callback be called?

This documentation seems related, but I am not familiar with the context as I have not used v5x.

Start with the subscription guide linked in the issue and compare it with the v6 migration example. Clarify how errors thrown inside a subscription are handled, including whether the subscription stops and whether completion is called, then update the documentation with a verified example.