Functional Enhancement

The functional change is in PendingBatch::allowFailures(), which now accepts:

• A boolean value (original behavior)
• A callable/Closure
• An array of callables/Closures

This allows the registration of callbacks that will be executed when a job fails, providing more granular control over failure handling in batch processing. The Batch class has been updated with corresponding methods to handle these new failure callbacks.

// New usage example:
$batch->allowFailures(function ($batch, $exception) {
    // Handle individual job failure
    Log::error("Job failed in batch {$batch->id}: {$exception->getMessage()}");
});

Of course, $batch->allowFailures() and $batch->allowFailures($boolean) still work as before.

Additional Changes

• Refactored callback invocation into a centralized invokeCallbacks method in the Batch class

Notes

• I debated going with $batch->failure($callback) instead of dual-purposing $batch->allowFailures(), but went with the latter since the former would require either a call to allowFailures() anyway, setting this option implicitly in the failure() implementation, or reworking the logic of allowsFailures() to also return true when failure callbacks are present. I'm open to reworking this in any of those directions.
• I'll add tests once the prior question is resolved.
• I envision a possible future JobContext object that would be passed to the callback providing more job specific detail, making this potentially more useful.