supabase / supabase-flutter / 39930064219

94%

push

github

fix(realtime)!: send broadcast data under payload without mutating the caller's map (#2036)

Linear:
https://linear.app/supabase/issue/SDK-2336/fixrealtime-sendbroadcastmessage-mutates-the-callers-map-and-uses-a

## What changed

- `send()` builds a new message map instead of writing `type` and
`event` into the map it was given. A `const` payload or a `Map<String,
int>` no longer throws, and a reused map no longer picks up extra keys.
- `sendBroadcastMessage()` now puts its `payload` under the `payload`
key of the message, the same shape `httpSend()`, database broadcasts and
realtime-js use. `payload` is now an `Object` like on `httpSend()`: a
`Map<String, dynamic>` is sent as JSON, binary data (`TypedData` or
`ByteBuffer`) is passed directly and sent as a binary frame, instead of
being nested under a `payload` key by hand.
- `onBroadcast` documents the message shape: `type`, `event`, the data
under `payload`, and `meta` for database broadcasts.
- The realtime and idioms skills, the `realtime_room` example, the
`supabase_flutter` README and MIGRATION.md use the new shape.
MIGRATION.md has a new section, also listed under the changes the
compiler will not catch, since a map payload still compiles. It calls
out callers who wrapped their data in a `payload` key themselves, which
now arrives nested twice.

## Verification of the shapes

Checked against the local stack (Realtime from the Supabase CLI) before
changing anything: `httpSend(event: 'http', payload: {'x': 1})` arrives
as `{type: broadcast, event: http, payload: {x: 1}}`, and
`realtime.send('{"x": 2}', 'db', topic, false)` arrives as `{type:
broadcast, event: db, payload: {x: 2, id: ...}, meta: {id: ...}}`. Only
`sendBroadcastMessage` put the data at the top level.

## Tests

- `broadcast_payload_test.dart`: wire shape, `const` payload,
`Map<String, int>` payload, the caller's map stays unchanged, binary
payload goes out as a binary frame, and a broadcast sent from Dart is
received in exactly the... (continued)

8 of 9 new or added lines in 1 file covered. (88.89%)

11251 of 12240 relevant lines covered (91.92%)

5.59 hits per line