supabase / supabase-flutter / 38230159408

92%

Build Type

push

github

Committed by web-flow

Commit Message

fix(realtime): keep a rejoining channel from unsubscribing itself (#1949)

Fixes #1942

## Problem

`RealtimeChannel.rejoin()` calls `leaveOpenTopic(topic)` to leave any
duplicate channel on the same topic. That lookup returned the first
joined or joining channel on the topic, which is the rejoining channel
itself whenever it is already joining or joined. The channel then
unsubscribed itself, reported `closed`, was removed from the client and
never received anything again.

This happens in practice after a reconnect: the socket rejoins errored
channels as soon as it opens, while the backoff timer scheduled at the
drop keeps running. If the server has not answered the join by the next
tick (about 2 s later), the tick rejoins a joining channel and it leaves
itself. Adding a presence listener to a joined channel without presence
hit the same path every time.

## Changes

- `leaveOpenTopic` takes the rejoining channel and skips it by identity,
so it only leaves real duplicates on the topic.
- `rejoinUntilConnected` no longer resends a join that is still waiting
for its reply. Resending would cancel the join in flight, so a server
slower than the backoff interval could never answer one. A join answered
with an error is still retried on the next tick.

## Tests

- New `rejoin_test.dart` covers a rejoin of a joined channel, the
presence listener resubscription, a duplicate channel on the same topic
still being left, and the rejoin timer with a pending and an errored
join.
- `mock_test.dart` "correct CHANNEL_ERROR data on heartbeat timeout"
expected a `closed` status that came from this bug. It now asserts that
the channel stays on the client with only the `channelError` status.


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Bug Fixes**
* Improved channel rejoining to avoid sending a duplicate join while a
reply is pending.
* Rejoining a channel no longer closes that same channel when another
open c... (continued)

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