supabase / supabase-flutter / 28613300326

86%

Build Type

push

github

Committed by web-flow

Commit Message

fix(realtime): preserve nested empty maps in Message.toJson() (#1518)

## What

`Message.toJson()` flattens nested maps by assigning into
`processedPayload[outerKey]` from inside a loop over the inner map's
keys. When the nested value is an **empty** map, that loop body never
runs, so the outer key is never assigned and disappears from the
serialized payload:

```dart
Message(
  topic: 'room:lobby',
  event: ChannelEvents.presence,
  payload: {'event': 'track', 'payload': <String, dynamic>{}},
).toJson();
// {topic: room:lobby, event: presence, payload: {event: track}}
//                                                 ^ the nested `payload` key is gone
```

## Why

A presence `track({})` (tracking with no metadata) and any
broadcast/send whose payload contains a nested empty map are sent to the
Realtime server **missing their `payload` field**. The initialization
`processedPayload[outerKey] ??= {}` lived inside the inner `for` loop,
so it was skipped entirely for an empty map.

Fix: initialize `processedPayload[outerKey]` to an empty map **before**
the loop, so an empty map round-trips as `{}` instead of vanishing.

## Not a breaking change

Non-empty nested maps serialize exactly as before (the initialization
simply moved ahead of the loop). Only the previously-dropped empty-map
case changes — it's now preserved.

## Tests

Added to `packages/realtime_client/test/message_test.dart`: a nested
empty map (`track({})` shape) is preserved, and a nested non-empty map
still serializes correctly. The empty-map test fails on the current code
(`Actual: {'event': 'track'}`) and passes with the fix. `dart format`
and `dart analyze --fatal-warnings` are clean.

Coverage Stats

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

1 existing line in 1 file now uncovered.

4218 of 4904 relevant lines covered (86.01%)

4.0 hits per line