Async actions: Action Scheduler driver and auto resolution

[ogorzalka]

Phase 2, step D: Action Scheduler driver and auto resolution.

action-scheduler driver

• Available when as_enqueue_async_action() exists and Action Scheduler is initialised (ActionScheduler::is_initialized()). Before action_scheduler_init its functions exist but cannot store anything. Never a Composer dependency.
• The payload travels whole as the action argument (decision of 7 October). onQueue() becomes the group, pollora by default. A delay uses as_schedule_single_action(), otherwise as_enqueue_async_action(). History is visible in Tools › Scheduled Actions.
• Long payloads: Action Scheduler refuses arguments over 8,000 characters as JSON, which a large capture() or, soon, a serialized closure can reach. Above 7,900, the payload is kept by PayloadStore (non-autoloaded option, claim on execution) and the action carries only its identifier. Rather than falling back to in-place execution, the work still goes through the queue.
• Retries go through Action Scheduler (driver recorded in the payload). A refused action throws AsyncException, and a payload kept apart is forgotten.

auto, now the default

• Resolves to the first available of Async::setAutoDrivers() (['action-scheduler', 'wp-cron']). Phase 3 will put the framework's queue first.
• Resolved on each dispatch, so a hook fired before Action Scheduler is initialised still queues, through WP-Cron.
• Behaviour change: a site with WooCommerce switches from WP-Cron to Action Scheduler on upgrade. Payloads already in WP-Cron still run, since the listener does not depend on the driver. POLLORA_ASYNC_DRIVER=wp-cron keeps the old behaviour. This is in the CHANGELOG.

Refactor

• PayloadStore takes the non-autoloaded storage and the claim out of WpCronDriver. WpCronDriver::OPTION_PREFIX, handles() and claim(), public since 1.2.0, are kept and delegate to it.
• The recovery task also leaves alone a payload whose Action Scheduler action is pending (as_has_scheduled_action()), so it never runs a delayed action early.

API fix

The PHPDoc of capture() and when() was callable(mixed...), which static analysis rejects for a closure with typed parameters such as fn (int $id) => …. It is now callable.

Tests

• Unit: 208 passed, 11 new for the driver (stubbed Action Scheduler, only available when a test asks).

• Real WordPress, now with the Action Scheduler plugin active, locally and in CI (wp plugin install action-scheduler --activate): 4 new tests, 10 in total.

  1. auto chooses Action Scheduler; the payload is whole in the pollora group; no WP-Cron event; the queue runs in a separate process and the handler runs.
  2. onQueue sets the group.
  3. A 9,000-character capture is kept apart and runs once.
  4. A retry goes through Action Scheduler.

  The suite's default driver stays wp-cron (fixture filter), so the earlier tests are unchanged.

• PHPStan level 5 and Pint pass.