Always getting the error parameter as 'undefined' in an onclose event of the SignalR Typescript client.

Hello,
I am trying to implement simple chat application using SignalR. For front-end, I am using Angular 10 with Typescript SignalR client. For this client I am using the latest @microsoft/signalr package. While the back-end server is in .Net Core 3.1 WebAPI project. Also, I am using the Azure SignalR service with Standard pricing tier.
I am referring the following documentation.
https://video2.skills-academy.com/en-us/javascript/api/@microsoft/signalr/hubconnection?view=signalr-js-latest#onclose--error---error-----void-
As per the documentation, the 'onclose' event receives an optional error parameter if there is any. But in my case in the client code, I am always getting this error as 'undefined'. I want to use this error parameter to determine if the connection was closed purposefully by client or was there any error either from client or server and based on that I want to take the further action in code. Find below my code snippet.

this.hubConnection.onclose((error) => {  
  // Try to log the error.  
  if (typeof error !== 'undefined') {  
    console.log(this.TAG + '(onclose) Error: ' + error.name + ' : ' + error.message);  
  } else {  
    console.log(this.TAG + '(onclose) No error to show while closing the connection.');  
  }  

  // Log the connection state.  
  console.log(this.TAG + '(onclose) HubConnection State: ' + this.hubConnection.state);  
});  

Kindly please take a look at this and let me know if I am doing it correctly or is there any other way to do this. Also, if you need more details about the issue, please let me know.

Thanks.