Eech heartbeat and channel join sends a new accessToken, even if token hasn't changed, same for channel join

[lauri865]

Bug report

• I confirm this is a bug with Supabase, not with my own application.
• I confirm I have searched the Docs, GitHub Discussions, and Discord.

Describe the bug

Each setAuth call sends a new access_token payload (all good):

realtime-js/src/RealtimeClient.ts

Lines 337 to 347 in 82e9966

	setAuth(token: string | null): void {
	this.accessToken = token
	this.channels.forEach((channel) => {
	token && channel.updateJoinPayload({ access_token: token })
	if (channel.joinedOnce && channel._isJoined()) {
	channel._push(CHANNEL_EVENTS.access_token, { access_token: token })
	}
	})
	}

Each sendHeartBeat call calls setAuth (even if accessToken hasn't changeD), which results in a lot of unnecessary messages being sent:

realtime-js/src/RealtimeClient.ts

Lines 553 to 574 in 82e9966

	private _sendHeartbeat() {
	if (!this.isConnected()) {
	return
	}
	if (this.pendingHeartbeatRef) {
	this.pendingHeartbeatRef = null
	this.log(
	'transport',
	'heartbeat timeout. Attempting to re-establish connection'
	)
	this.conn?.close(WS_CLOSE_NORMAL, 'hearbeat timeout')
	return
	}
	this.pendingHeartbeatRef = this._makeRef()
	this.push({
	topic: 'phoenix',
	event: 'heartbeat',
	payload: {},
	ref: this.pendingHeartbeatRef,
	})
	this.setAuth(this.accessToken)
	}

Also, each call to join a channel triggers new call to access_token, even though the accessToken is also sent with the phx_join event already.

Are we being charged for all these unnecessary messages being sent?

[lauri865]

We removed those additional payloads, and everything seems to be working fine at initial look:

• No access token sent with every heartbeat (gets rid of 2 extra messages per minute per each connection, much larger payloads than the heartbeats themselves)
• If access token hasn't changed – skip the message.event === "access_token" (gets rid of 1 extra message per each page view)

We did it on a custom transport level for now.

[filipecabaco]

this is the expected behaviour, this are not accounted for for you total messages and if they don't change our server just ignores the message so this is low impact on client and server.

could you provide more information why could be a bigger concern?