supabase / supabase-swift / 24844914410

81%

Build Type

push

github

Committed by web-flow

Commit Message

fix(realtime): resolve subscribe/unsubscribe lifecycle races via ChannelStateManager actor (#974)

* refactor(realtime): extract ChannelStateManager actor for subscription lifecycle

Moves the subscribe/unsubscribe state machine out of RealtimeChannelV2 and
into a dedicated ChannelStateManager actor, mirroring the ConnectionManager
pattern introduced in #855.

The actor owns the full lifecycle (unsubscribed → subscribing → subscribed
→ unsubscribing → unsubscribed): retries, timeouts, server-confirmation
waits, and deduplication of concurrent calls. Network side-effects
(phx_join, phx_leave, makeRef, ensure-connected) are injected as closures,
keeping the state machine independent of the concrete channel.

Key behaviours:
- Synchronous stateDidChange callback forwards transitions to the channel's
  status subject without an async hop, so status reads right after
  subscribe() returns see the latest value.
- beginSubscribe uses withTaskCancellationHandler so cancelling the caller
  cancels the in-flight retry loop (previously Task.value kept waiting).
- runUnsubscribe waits (bounded by timeoutInterval) for the server's
  phx_close when coming from .subscribed, matching pre-refactor semantics.
  When aborting an in-flight subscribe there's no live session, so the
  wait is skipped.

Net result: RealtimeChannelV2.swift shrinks by 154 lines; 16 new unit
tests cover the state machine directly.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* fix(realtime): close three ChannelStateManager races found in review

- Move `clientChanges` buffer from the actor to a `LockIsolated` on the
  channel. `onPostgresChange` now writes synchronously, eliminating a
  fire-and-forget `Task` that could lose the race against a subsequent
  `subscribe()` (causing `phx_join` to ship without any filter).

- Make push registration atomic against `joinRef`. `push()` no longer
  does two actor hops (`joinRef` then `storePush`); it calls a single
  `storePushIfJoinRefMat... (continued)

Coverage Stats

304 of 344 new or added lines in 2 files covered. (88.37%)

4 existing lines in 1 file now uncovered.

7103 of 8770 relevant lines covered (80.99%)

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