Realtime-js returns "SUBSCRIBED" message before websocket returns subscribed message 2 to 3 seconds later.

[GaryAustin1]

Bug report

Describe the bug

I'm putting this in realtime as it might involve realtime and realtime-js.

First it appears realtime takes 1 to several seconds to set up a subscription successfully to handle a change report, is this expected?

Second supabase-js (rc4) / realtime-js .subscribe() fires a SUBSCRIBED event well before the websocket returns a subscribed message in a packet.

To Reproduce

let mySubscription = await supabase
    .channel('public.subscribe:uid=eq.'+user.id)
    .on('postgres_changes',
        { event: '*', schema: 'public', table: 'subscribe',filter:'uid=eq.'+user.id }, (payload) => {
        console.log('Change received!', payload)
        }
    })
    .subscribe((status)=>{
        console.log('subscribe = status',status);
        if (status==='SUBSCRIBED') {
            online.set(true);
        }
        else if (status !== 'CLOSED') {
            online.set(false)
        }
    })

if ($online) {          //simplified but online is a Sveltekit state variable that gets set when 'SUBSCRIBED' is received.
    console.log('online now')
    let timer = 2000
    setTimeout(function() {
    console.log('online do update delay by ',timer)

    supabase.from('status').update({'update_note_counter': 9}).eq('uid', '74fa50d7-e8a2-4ce7-b894-4e4f3ba75849')
        .then(result => console.log('update returned', result))
    }, timer);

Expected behavior

.subscribe() should not return 'SUBSCRIBED' until channel is ready to report changes in database
OR provide proper way to get status of channel when it is ready to handle changes.
This is critical for successful use of realtime as one needs to load initial data copy when realtime is setup and ready to report changes and not before (especially if many seconds).

Confirmation from Supabase that realtime can take several seconds to be ready to report changes.

Screenshots

A failure with 2 second delay to an update operation, and a subscribe message in websocket around 3 seconds.
The .subscribe() returns subscribed 24.221 and the websocket appears to return subscribed 27.139

A success with 4 second delay to an update operation, and a subscribe message in websocket around 2 seconds.

System information

2.0.0-rc4 supabase.js
Supabase hosted instance

Additional context

This issue was reported in supabase/supabase issues on v1 js. #282

[w3b6x9]

@GaryAustin1 thanks for the detailed report! will close this in favor of #282.