Streams not showing delete event

[maxfornacon]

Describe the bug
Streams don't react to deleted records.

I use a stream like this:

                StreamBuilder(
                  stream: Supabase.instance.client
                      .schema('xxx')
                      .from('notifications')
                      .stream(primaryKey: ['id'])
                      .eq('employee_id', '9418ce33-6349-45aa-895e-78e4423155dc'),
                  builder: (context, snapshot) {
                    if (snapshot.hasData) {
                      return Text('StreamBuilder1: ${snapshot.data!.length}');
                    } else {
                      if (snapshot.error != null) {
                        print('ERRROR1: ${snapshot.error.toString()}');
                      }
                      return const Text('StreamBuilder1: No data');
                    }
                  }
                )

It works when I add rows to the table, then the snapshot.data!.length increments, but when I delete entries, it doesn't decrement.

I also listen to the channel like this at the same time:

 var channel = Supabase.instance.client
        .channel('notifications')
        .onPostgresChanges(
      event: PostgresChangeEvent.all,
      schema: 'xxx',
      table: 'notifications',
      callback: (payload) {
        print('Change received: ${payload.toString()}');
      },
    ).subscribe();

Here it receives the delete event.

To Reproduce
Steps to reproduce the behavior:

1. length = 0
2. I add a row to table --> length = 1
3. I delete that row --> length = 1 still
4. I add a new row --> length = 2

Expected behavior
Stream gets notified about the delete event.

Version (please complete the following information):
Testing on macOS:

Happens for me on supabase_flutter: 2.6.0 (hosted) and the version from branch fix/realtime

[dshukertjr]

@maxfornacon
In your stream, you have an eq filter, but in your realtime subscription, you don't. Have you tried applying an eq filter on the realtime subscription as well?

[maxfornacon]

@dshukertjr
When I apply the eq filter to the realtime subscription, it seems to not receive the changes as well.

[dshukertjr]

Thanks for the confirmation. I can see that other users are having the same trouble.
supabase/realtime#1154

I will ask the realtime team to look into this one.

[dshukertjr]

@maxfornacon
Actually, could you verify that you have set the replica identity to full? I was able to get it to work with it.
https://supabase.com/docs/guides/realtime/postgres-changes#receiving-old-records

[maxfornacon]

You mean this? I have everything activated. And I didn't change anything recently when I remember correctly.

[dshukertjr]

@maxfornacon No, it's not that one. Sorry, I thought I pasted the link to the relevant sections, but you need to run this SQL statement.
https://supabase.com/docs/guides/realtime/postgres-changes#receiving-old-records

[maxfornacon]

This fixed it for me too. Thanks!

But why did it only happen when I applied the filter? When the realtime subscription printed out the received change it looked like this:

PostgresChangePayload(schema: ..., table: notifications, commitTimestamp: 2024-09-14 14:21:48.288Z, eventType: PostgresChangeEvent.delete, newRow: {}, oldRow: {id: 79575cff-c09b-4588-9556-83e1190de528}, errors: null)

So the old record was received and only the id of it. That indicates that it was set to full as it says int the docs:

When RLS is enabled and replica identity is set to full on a table, the old record contains only the primary key(s).

[dshukertjr]

My guess is it's related to this update: supabase/walrus#76