how to use the replaysubject function from the rxjs library in javascript

ReplaySubject is a type of subject in rxjs that allows you to replay events to future subscribers. It can be useful when you need to capture an entire event stream and replay it to subscribers that come late to the party.

Here is an example of how to use the ReplaySubject function in rxjs:

index.tsx
// import the ReplaySubject function from rxjs
import { ReplaySubject } from 'rxjs';

// create a new ReplaySubject with a buffer of 2 events
const myReplaySubject = new ReplaySubject(2);

// subscribe to the subject and log each event
myReplaySubject.subscribe(event => console.log(`Event: ${event}`));

// push some events to the ReplaySubject
myReplaySubject.next('Event 1');
myReplaySubject.next('Event 2');
myReplaySubject.next('Event 3');

// subscribe to the subject again, even though it's past the buffer size
myReplaySubject.subscribe(event => console.log(`Late event: ${event}`));

// Output:
// Event: Event 1
// Event: Event 2
// Event: Event 3
// Late event: Event 2
// Late event: Event 3
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In this example, we created a new ReplaySubject with a buffer size of 2 events. We then subscribed to the subject and logged each event.

Next, we pushed 3 events to the ReplaySubject. Even though we only had a buffer size of 2 events, all 3 events were captured by the subject.

Finally, we subscribed to the subject again, even though it was past the buffer size. The ReplaySubject "replayed" the last 2 events to the latest subscriber, resulting in both 'Event 2' and 'Event 3' being logged again.

Hope that helps!