Handle reconnection for `godot-socketio` by garciaf · Pull Request #7 · msabaeian/godot-socketio

garciaf · 2026-04-05T06:14:56Z

Bug fixes

`_on_noop()` treated NOOP as an error

NOOP is a normal Engine.IO packet sent during polling to unblock a long-poll request. The handler was calling push_error(). It now calls _poll(), matching the behaviour of _on_message().

`disconnect_socket()` emitted `socket_disconnected` twice

disconnect_socket() called engine_close() which already emits engine_connection_closed → _on_engine_io_connection_closed() → socket_disconnected. The duplicate direct socket_disconnected.emit() at the end of disconnect_socket() was removed.

Upgrade PONG and heartbeat PONG not distinguished

_on_pong() was unconditionally triggering the WebSocket upgrade flow. It now receives the raw payload and only upgrades when the payload is "probe", correctly ignoring plain heartbeat PONGs from the server.

`State` and `TransportType` enum type annotation error

In Godot 4, inner enums on a class_name class cause a type mismatch between the unqualified (State) and fully qualified (EngineIO.State) names when used as type annotations. Removed the explicit type annotations on state and _transport_type, letting GDScript infer them from their initialisers.

Client-initiated PINGs broke Engine.IO v4

In Engine.IO v4 only the server sends PINGs — client-initiated PINGs are v3 behaviour and cause the server to disconnect with transport error. A heartbeat timer that was sending unsolicited PINGs on pingInterval has been removed. The existing _on_ping() → PONG response path is sufficient for keepalive.

New feature: automatic reconnection

When the WebSocket closes unexpectedly, the client now attempts to reconnect automatically with linear backoff instead of immediately calling engine_close().

Three new exported variables are exposed in the Inspector:

Variable	Default	Description
`auto_reconnect`	`true`	Enable/disable automatic reconnection
`max_reconnect_attempts`	`5`	Give up after this many attempts
`reconnect_base_delay`	`1.0`	Delay multiplied by attempt count (1 s, 2 s, 3 s…)

A new signal reconnect_attempt(attempt: int, max: int) is emitted on each retry so the game UI can show feedback like "Reconnecting 2/5…".

On a successful reconnection _reconnect_attempts resets to 0 at both success paths (polling in _on_open, WebSocket in _on_pong). If all attempts are exhausted, engine_close() is called normally and engine_connection_closed fires once.

- Implement reconnect logic - Handle _on_noop

garciaf · 2026-04-06T12:34:35Z

Thanks again for this amazing addon @msabaeian, thanks to you, I could make my card game so much more reliable.
It worked like a charm.

If this PR makes sense to you, I am really happy to contribute; otherwise, I will remain on the fork I have.

Thanks again for taking care of such a complicated problem

msabaeian · 2026-04-16T11:59:25Z

Hey @garciaf! thanks for your work! I’ll review this in the coming week and if everything looks good, merge it.
sorry for the late response I kinda lost track of this repo

garciaf · 2026-04-20T07:53:01Z

All good @msabaeian if you want to review it in the game I am working on, I can give you further access to the prototype I have.

But basically, I use this plugin to allow people to play the Godot game on their phone (With a web browser).

And Socket IO is so much more reliable than Websocket. Your work is incredible.
Also, I fixed a small typo in this PR to allow working with Godot 4.6

msabaeian

thanks for your effort, i've some question and suggestions

msabaeian · 2026-04-24T13:29:44Z


 var session_id: String = ""
-var state: State = State.DISCONNECTED
+var state = State.DISCONNECTED


Question: why removing state type?

@msabaeian This was failing on Godot 4.6
maybe I could try

var state := State.DISCONNECTED

But Godot 4.6 would fail at this point. I would need to investigate the nature of the error

msabaeian · 2026-04-24T13:30:24Z

 @export var path: String = "/engine.io"
+@export var auto_reconnect: bool = true
+@export var max_reconnect_attempts: int = 5
+@export var reconnect_base_delay: float = 1.0


Nit: it would be good to mention type of this value, seconds or milliseconds

Very good point.

would

@export var reconnect_base_delay_seconds: float = 1.0

Be what you think? Do you have some conventions in the project? When it comes to defined durations?

msabaeian · 2026-04-24T13:31:06Z

 signal engine_connection_closed()
 signal engine_message_received(data: String)
 signal engine_transport_upgraded()
+signal reconnect_attempt(attempt: int, max: int)


Suggested change

signal reconnect_attempt(attempt: int, max: int)

signal reconnection_attempted(attempt: int, max: int)

msabaeian · 2026-04-24T13:35:23Z

-		engine_close()
+		if auto_reconnect and _reconnect_attempts < max_reconnect_attempts:
+			_reconnect_attempts += 1
+			reconnect_attempt.emit(_reconnect_attempts, max_reconnect_attempts)


Question: wouldn't it better to emit this after attempting not before it? not sure what's the behavior in socketio library itself

We could indeed but since everything is wired via signal we technically do not know when this is done. But I could put right after t.start()
That's what you have in mind right?

msabaeian · 2026-04-24T13:38:18Z

+			session_id = ""
+			state = State.DISCONNECTED
+			_websocket = null
+			_polling_http_request = null
+			_send_data_http_request = null
+			_send_data_queue.clear()
+			_probe_sent = false
+			_transport_type = TransportType.POLLING
+			_ping_interval = 0
+			_pong_timeout = 0
+			_max_payload = 0


Suggested change

session_id = ""

state = State.DISCONNECTED

_websocket = null

_polling_http_request = null

_send_data_http_request = null

_send_data_queue.clear()

_probe_sent = false

_transport_type = TransportType.POLLING

_ping_interval = 0

_pong_timeout = 0

_max_payload = 0

_clear_values()

Very very convenient! Noiceee

msabaeian · 2026-04-24T13:41:19Z

 		disconnect_namespace(ns)

 	engine_close()
-	socket_disconnected.emit()


nice catch!

msabaeian · 2026-04-24T14:14:43Z


-func _on_pong():
+func _on_pong(payload: String = ""):
+	if payload != "probe":


i don't think socketio ever sends a pong packet which doesn't have probe, but let's add a warning here in case of those unexpected scenarios

Not a failing one, right? Just a warning in the console?
What do you use usually?

garciaf · 2026-05-04T08:50:54Z

@msabaeian thank you so much for looking into it and very good comment. I will fix it and push it.

We might also consider chaning the Readme afterward.

[FEATURE] Implement reconnect and noop handler

25e169e

- Implement reconnect logic - Handle _on_noop

garciaf changed the title ~~[FEATURE] Implement reconnect and noop handler~~ ## Bug fixes and reconnection for godot-socketio Apr 5, 2026

garciaf marked this pull request as ready for review April 5, 2026 06:22

garciaf changed the title ~~## Bug fixes and reconnection for godot-socketio~~ Handle reconnection for godot-socketio Apr 5, 2026

msabaeian self-requested a review April 16, 2026 12:04

msabaeian reviewed Apr 25, 2026

View reviewed changes

	signal reconnect_attempt(attempt: int, max: int)
	signal reconnection_attempted(attempt: int, max: int)

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garciaf commented Apr 5, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Bug fixes

_on_noop() treated NOOP as an error

disconnect_socket() emitted socket_disconnected twice

Upgrade PONG and heartbeat PONG not distinguished

State and TransportType enum type annotation error

Client-initiated PINGs broke Engine.IO v4

New feature: automatic reconnection

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garciaf commented Apr 6, 2026

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msabaeian commented Apr 16, 2026

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garciaf commented Apr 20, 2026

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garciaf commented May 4, 2026

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garciaf commented Apr 5, 2026 •

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`_on_noop()` treated NOOP as an error

`disconnect_socket()` emitted `socket_disconnected` twice

`State` and `TransportType` enum type annotation error