supabase / supabase-flutter / 27970805559

85%

Build Type

push

github

Committed by web-flow

Commit Message

fix(realtime_client): detect dropped connections on iOS via WebSocket ping (#1451)

## What

Enable `pingInterval` on the native (`dart:io`) WebSocket so dropped
connections are detected consistently across platforms.

## Why

Fixes #1071. When the internet drops, Android emits a
`RealtimeSubscribeException` (close code 1002) but iOS emits nothing,
leaving the stream silently stale.

**Root cause:** `createWebSocketClient` created the native WebSocket
without a `pingInterval`, so a *silently* dropped connection was never
detected at the socket layer:

- On **Android**, the OS surfaces the dead TCP connection promptly (RST
→ close code 1002), so `onDone`/`onError` fires and `_triggerChanError`
propagates a `channelError`.
- On **iOS**, the OS buffers writes instead of surfacing a reset. The
only fallback was the app-level Phoenix heartbeat, whose recovery path
calls `conn.sink.close()`, which does not reliably fire `onDone` on a
dead iOS socket. So nothing propagated to the channel.

## How

Set `pingInterval` (new `Constants.defaultWebSocketPingInterval`, 25s,
aligned with the existing heartbeat cadence) on the native WebSocket.
`dart:io` now actively probes the peer and closes the connection
(`goingAway`) when a pong is not received, which flows through the same
`onDone → _onConnClose → _triggerChanError → reconnect` path Android
already uses.

## Scope / safety

- Only the default native transport changes. Web (`websocket_web.dart`)
is untouched, since browsers manage ping/pong internally.
- Custom transports injected via `RealtimeClientOptions.transport` are
unaffected.
- No public API change: the `WebSocketTransport` typedef is unchanged.
- A 25s pong window is generous for mobile round-trips.

## Testing

- `dart analyze` clean on the changed files.
- Realtime unit suite passes (`socket_test`, `mock_test`,
`channel_test`, including the existing
CHANNEL_ERROR-on-heartbeat-timeout test).
- Files formatted.

No unit test added: `pingInterval` is a p... (continued)

Coverage Stats

1 of 1 new or added line in 1 file covered. (100.0%)

34 existing lines in 3 files now uncovered.

4101 of 4814 relevant lines covered (85.19%)

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