Fix connection not resuming after guest user goes to background

[nuno-vieira]

🔗 Issue Links

#3338
https://linear.app/stream/issue/IOS-75/[reconnection]-[github]-websocket-disconnectes-when-guest-user-comes

🎯 Goal

Fixes connection not resuming after guest user goes to background

📝 Summary

• Fixes connection not resuming after guest user goes to background
• Improves Demo App Token Refreshing UX

🛠 Implementation

The root of the problem was that, in a previous PR, we introduced stopping the recovery handler on disconnect().
The reason why this is problematic is because of how our connect works. Especially for guest users and anonymous users, we have logOutFirst: true. This means that when connecting guest users and anonymous users, we will always logout first, and this means we call disconnect() which will stop the recovery handler. So the next time the user goes to background, the recovery handler will not be running, and so, it won't reconnect automatically. Here is the flow:

flowchart LR 
    B["ChatClient.connectUser()"]
    B --> C["RecoveryHandler.start()"]
    C --> D{logOutFirst?}
    D -->|Yes| E["ChatClient.logout()"]
    E --> F["RecoveryHandler.stop()"]
    F --> G["authRepository.connect()"]
    D -->|No| G

Loading

So the problem is that when we logout a user first, and then connect it back again, we do not call again start() on the recovery handler. Changing this would require a bit of a refactoring so better to play safe and simple for now.

All of this means that this could happen even for a regular user, not only guest users. If a regular user is logged in, then disconnects (without logging out) and then connects with a different user, and then going to background, it would happen the same issue, although this flow is quite rare and usually means a bad integration, since for different users, customers should always logout.

🧪 Manual Testing Notes

• Open Demo App Configuration
• Disable staysConnectedInBackground
• Login with Guest User
• Go to background, wait 5s to make sure everything is disconnected
• Go back to foreground
• Connection should resume

☑️ Contributor Checklist

• I have signed the Stream CLA (required)
• This change should be manually QAed
• Changelog is updated with client-facing changes
• Changelog is updated with new localization keys
• New code is covered by unit tests
• Comparison screenshots added for visual changes
• Affected documentation updated (docusaurus, tutorial, CMS)

[Stream-SDK-Bot]

SDK Size

title	develop	branch	diff	status
StreamChat	6.92 MB	6.92 MB	0 KB	🟢
StreamChatUI	4.95 MB	4.95 MB	0 KB	🟢

[Stream-SDK-Bot]

SDK Performance

target	metric	benchmark	branch	performance	status
MessageList	Hitches total duration	10 ms	11.68 ms	-16.8% 🔽	🔴
	Duration	2.6 s	2.55 s	1.92% 🔼	🟢
	Hitch time ratio	4 ms per s	4.59 ms per s	-14.75% 🔽	🔴
	Frame rate	75 fps	78.12 fps	4.16% 🔼	🟢
	Number of hitches	1	1.2	-20.0% 🔽	🔴

[sonarcloud]

Quality Gate passed

Issues
164 New issues
0 Accepted issues

Measures
0 Security Hotspots
84.4% Coverage on New Code
0.1% Duplication on New Code

See analysis details on SonarCloud

[laevandus]

Seems to be safe because recovery handler checks for current connection state and does not attempt to reconnect if the state is disconnected with userInitiated. 🤔

var canReconnectFromOffline: Bool {
        …
        switch webSocketClient.connectionState {
        case .disconnected(let source) where source == .userInitiated:
            return false

[nuno-vieira]

Yes exactly the reconnection handler although alive, it won't do nothing