how to use the objectunsubscribederror function from the rxjs library in typescript

To use the ObjectUnsubscribedError function from the RxJS library in TypeScript, you can import it from the rxjs package and then use it to handle errors that occur when an observer attempts to subscribe to a completed or unsubscribed observable.

Here is an example implementation:

index.ts
import { Observable, Subject, ObjectUnsubscribedError } from 'rxjs';

const subject = new Subject<number>();

// Emit some values and then complete the subject
subject.next(1);
subject.next(2);
subject.next(3);
subject.complete();

// Create an observer and subscribe to the subject
const observer = {
   next: value => console.log(value),
   error: error => {
      if (error instanceof ObjectUnsubscribedError) {
         console.log('Observer attempted to subscribe to a completed or unsubscribed Observable.');
      } else {
         console.log('Error:', error);
      }
   },
   complete: () => console.log('Observer completed.')
}

subject.subscribe(observer);
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In this example, we create a Subject, add some values to it, and then complete it. We then create an observer with callbacks for next, error, and complete and subscribe it to the subject. In the error callback, we check if the error is an instance of ObjectUnsubscribedError and handle it accordingly. If it is not an instance of that error, we log the error message to the console. Finally, we log a message to the console when the observer completes.