SocketModeClient still fails to automatically reconnect when apps.connections.open API returns an error code

[levenleven]

We recently upgraded @slack/socket-mode to 1.3.1 to address https://github.com/slackapi/node-slack-sdk/issues/1495, but it seems there're still some unhandled scenarios where it wouldn't reconnect automatically.

This time the pattern is exactly the same as in https://github.com/slackapi/node-slack-sdk/issues/1495, but the error code is fatal_error (vs internal_error). Restarting the process fixed the issue. See the repro steps below with more logs.

Packages:

Select all that apply:

• [ ] @slack/web-api
• [ ] @slack/rtm-api
• [ ] @slack/webhooks
• [ ] @slack/oauth
• [x] @slack/socket-mode
• [ ] I don't know

Reproducible in:

The Slack SDK version

any version including 1.3.1

Node.js runtime version

any

OS info

any

Steps to reproduce:

[INFO] A pong wasn't received from the server before the timeout of 5000ms!
[INFO] Reconnecting to Slack ...
[INFO] Going to establish a new connection to Slack ...

[ERROR] Failed to retrieve a new WSS URL for reconnection (error: Error: An API error occurred: fatal_error)
[WARNING] Failed to start a Socket Mode connection (error: An API error occurred: fatal_error)

And then endless loop of:

[ERROR] Failed to send a message as the client is not ready
[ERROR] An unhandled error occurred while Bolt processed (type: event_callback, error: Error: Failed to send a WebSocket message

Expected result:

The SocketModeClient automatically reconnects when the server-side started working again.

Actual result:

The reconnection does not happen.

[seratch]

@levenleven Thanks for sharing this. The situation where the server returns fatal_error is not a common situation and it is clearly an issue on the server side. As long as the error response continues, the Socket Mode client app is unable to automatically reconnect. I am not sure why restarting the client helps. I cannot tell when and how this can be improved yet but, once we get new information on this, our team will update you.

[nazmariam]

Hello, @seratch we've received a similar error but without (error: An API error occurred: fatal_error)

Error details: Error: Failed to send a WebSocket message as the client is not ready, retry num: undefined, retry reason: undefined

Could it have the same reason? Thank you.

[filmaj]

I can validate this issue. Will send a PR with a test and a fix.