README

🧰 Provides Symfony Messenger middlewares tailored for exception handling. You can easily re-raise exceptions, chain them, or handle with a dedicated bus.

Installation 📥

Install via composer

composer require phphd/exception-handler-bundle

Enable the bundle in the bundles.php

PhPhD\ExceptionHandlerBundle\PhdExceptionHandlerBundle::class => ['all' => true],

Configuration ⚒️

To leverage features of this bundle, you should add phd_exception_handler middleware to the list:

framework:
    messenger:
        buses:
            command.bus:
                default_middleware: false
                middleware:
+                   - phd_exception_handler
                    - validation
                    - doctrine_transaction

The core principle of exception handling revolves around the idea of exceptions being dispatched to their corresponding bus, therefore each message bus must define respective exception bus.

The exception bus name convention is straightforward:command.bus exceptions are forwarded into command.exception.bus.

framework:
    messenger:
        buses:
            command.exception.bus:
                default_middleware: false
                middleware:
                    - phd_exception_rethrow_unhandled
                    - phd_exception_chaining
                    - phd_exception_result_filter
                    -   handle_message:
                            - true

Currently, there are few exception handling middlewares provided.

Rethrowing unhandled

Middleware: phd_exception_rethrow_unhandled

In case if dispatched exception had not been handled it is rethrown back.

Exception chaining

Middleware: phd_exception_chaining

Implements automatic exceptions escalation logic with #[RaiseAs] attribute.

Result filter

Middleware: phd_exception_result_filter

Filters out all null results of exception handlers.

Usage 🚀

Re-Raising Exceptions

The simplest use-case is defining #[RaiseAs] attribute on your exception class:

#[RaiseAs(AccessDeniedHttpException::class, bus: 'command.exception.bus')]
final class NonWhiteListedUserException extends DomainException
{
}

In this example, any time NonWhiteListedUserException is thrown from an underlying handler, it will be raised as AccessDeniedHttpException.

As you can see, there's required attribute bus option. Since some exceptions could be thrown from multiple different scenarios (hence, different buses), it is required to explicitly specify the bus from which the particular exception must be raised, so that in other scenarios another exceptions could be escalated:

#[RaiseAs(ImportLockedHttpException::class, bus: 'query.exception.bus')]
#[RaiseAs(RecoverableMessageHandlingException::class, bus: 'consumer.exception.bus')]
final class ImportLockedException extends RuntimeException
{
}

In previous example, ImportLockedException could be thrown either in http context (query.bus), or in the consumer context (consumer.bus). Therefore, raised exceptions are different.

Manual Handling

The exception is dispatched down to your custom handlers, where you could either return a Response, throw a new exception, or just return null so that exception will be thrown again.

#[AsMessageHandler('command.exception.bus')]
final readonly class InventoryExceptionHandler
{
    /** @throws Throwable */
    public function __invoke(InventoryDomainException $exception, InventoryCommand $command): ?Response
    {
        if ($exception instanceof JournalHasUnInventoriedItemException) {
            $data = $this->formatJournalException($exception);

            return new JsonResponse($data, Response::HTTP_BAD_REQUEST);
        }

        if ($exception instanceof StockItemNotVaildatedException) {
            $data = $this->formatItemException($exception, $command->getJournal());

            throw new StockItemNotValidatedHttpException($data, $exception);
        }

        return null;
    }
}

If you would like to use the same exception handler for multiple exception buses, you can do so using following more verbose message handler registration syntax:

#[AutoconfigureTag('messenger.message_handler', [
    'handles' => InventoryDomainException::class, 
    'bus' => 'command.exception.bus',
])]
#[AutoconfigureTag('messenger.message_handler', [
    'handles' => InventoryDomainException::class, 
    'bus' => 'query.exception.bus'
])]
final readonly class InventoryExceptionHandler
{
    // ...
}

phphd / exception-handler-bundle

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