getChannels() crashes on servers returning an empty channels array — the guard exists in process_trigger_result() but not here

Summary

getChannels() calls get_object_vars() without a type check, so a server response where channels is an empty JSON array crashes the client:

TypeError: get_object_vars(): Argument #1 ($object) must be of type object, array given
  src/Pusher.php:664

The interesting part: this library already guards against exactly this, but only on one code path.

process_trigger_result() (added in #323, fixing #322) checks the type:

https://github.com/pusher/pusher-http-php/blob/master/src/Pusher.php#L1195-L1197

if (property_exists($result, 'channels') && is_object($result->channels)) {
    $result->channels = get_object_vars($result->channels);
}

getChannels() does not:

https://github.com/pusher/pusher-http-php/blob/master/src/Pusher.php#L660-L666

public function getChannels(array $params = []): object
{
    $result = $this->get('/channels', $params);

    $result->channels = get_object_vars($result->channels);

    return $result;
}

Why it happens in practice

Pusher-protocol implementations other than Pusher itself are common now (Reverb, Sockudo, Soketi). I hit this with Laravel Reverb v1.11.1, which serialises an empty channel list as [] instead of {} — I reported it there as laravel/reverb#402, and it should be fixed on their side too.

But the failure mode is worth guarding here regardless, because it is silent and intermittent: the response is an array only while no channel is occupied. One connected client turns the PHP array into a string-keyed map, json_encode emits an object, and the crash disappears. So it reproduces on idle systems and vanishes under load.

Measured side by side, same signed request:

Reverb   →  {"channels":[]}
Sockudo  →  {"channels":{}}

Suggestion

Apply the same guard that process_trigger_result() already uses:

$result->channels = is_object($result->channels) ? get_object_vars($result->channels) : (array) $result->channels;

This keeps the documented return shape (channels as an array of channel names) for every server, instead of a fatal error for some of them. Happy to send a PR.

Environment

• pusher/pusher-php-server ^7.2
• PHP 8.3

Start in src/Pusher.php at getChannels(), then compare its channels handling with process_trigger_result(), which already guards non-object responses. Exercise the method with an empty channels array and verify it returns the documented array shape without a TypeError; run the relevant project tests to confirm existing behavior remains intact.