Previously, getting disconnected while waiting for an acknowledgement
would create a memory leak, as the acknowledgement was never received
and the handler would stay in memory forever.
This commit fixes the issue:
- handlers that do accept an error as first argument, such as:
* `socket.emit("test", (err, value) => { ... })` with `ackTimeout` option
* `socket.timeout(5000).emit("test", (err, value) => { ... })`
* `const value = await socket.emitWithAck("test")`
will now properly resolve with an error and get discarded.
- handlers that don't like `socket.emit("test", (value) => { ... });`
will simply be discarded upon disconnection
Note: the structure of the 'acks' attribute has been left untouched, in
order to prevent any breaking change.
Related:
- https://github.com/socketio/socket.io-client/issues/1546
- https://github.com/socketio/socket.io/issues/4964
Details:
- engine.io-client sets clearTimeoutFn and setTimeoutFn function
depending on settings passed to manager
- socker.io-client is using manager.setTimeoutFn to start connection
monitoring timer, but is using regular clearTimeout function to
stop it when connection is established
- in some setups it is causing timer fail to stop and it will break
connection every _timeout_ milliseconds (which is 20000 by default)
In some specific cases (Node.js client with WebSocket only), the reason
attached to the "connect_error" event was "websocket error" instead of
"timeout".
Related: https://github.com/socketio/socket.io/issues/4062
The packet ID cannot be used for deduplication, because it's only
unique for the given session. If you reconnect on another server and
try to resend a packet, then the server won't be able to know whether
the packet has already been processed or not.
This bug was introduced in [1]: a multiplexed socket could in some
cases send multiple CONNECT packets, resulting in duplicate connections
on the server side.
A cached socket will now be reopened only if it was inactive, that is,
if one had explicitly called socket.disconnect() before.
Related: https://github.com/socketio/socket.io-client/issues/1460
[1]: b7dd891e89
In the previous implementation added in [1], the socket would try to
send the packet even if it was disconnected, which would needlessly
exhaust the number of retries.
[1]: 655dce9755
Syntax:
```js
const socket = io({
retries: 3,
ackTimeout: 10000
});
// "my-event" will be sent up to 4 times (1 + 3), until the server sends an acknowledgement
socket.emit("my-event", (err) => {});
```
Notes:
- the order of the packets is guaranteed, as we send packets one by one
- the same packet id is reused for consecutive retries, in order to
allow deduplication on the server side
This commit adds some syntactic sugar around acknowledgements:
```js
// without timeout
const response = await socket.emitWithAck("hello", "world");
// with a specific timeout
try {
const response = await socket.timeout(1000).emitWithAck("hello", "world");
} catch (err) {
// the server did not acknowledge the event in the given delay
}
```
Note: enviroments that do not support Promises ([1]) will need to add a
polyfill in order to use this feature
See also: 184f3cf7af
[1]: https://caniuse.com/promises
Connection state recovery allows a client to reconnect after a
temporary disconnection and restore its state:
- id
- rooms
- data
- missed packets
See also: 54d5ee05a6
zuul is now archived [1] and does not support the new W3C WebDriver
protocol, since it relies on the wd package [2] under the hood, which
uses the (now deprecated) JSON Wire Protocol.
We will now use the webdriver.io test framework, which allows to run
our tests in local and on Sauce Labs (cross-browser and mobile tests).
This allows us to run our tests on latest versions of Android and iOS,
since Sauce Labs only supports the W3C WebDriver protocol for these
platforms ([3]).
[1]: https://github.com/defunctzombie/zuul
[2]: https://github.com/admc/wd
[3]: https://docs.saucelabs.com/dev/w3c-webdriver-capabilities/
