Messaging

• Introduction
• Publishing to RabbitMQ
• Testing Code That Publishes

Introduction

Sukarix\Messaging\CommandPublisher is a small interface for publishing JSON commands onto a message bus — telling another service to do something, as opposed to the request/response of a web action or the work-queue polling of Queues:

interface CommandPublisher
{
    public function publish(string $routingKey, array $payload): void;
}

Two implementations ship with the framework:

• Sukarix\Messaging\AmqpPublisher — publishes onto a direct-exchange RabbitMQ bus.
• Sukarix\Messaging\RecordingPublisher — records published messages in memory instead of sending them, for tests.

Publishing to RabbitMQ

use Sukarix\Messaging\AmqpPublisher;

$publisher = new AmqpPublisher($dsn, $exchange);
$publisher->publish('user.created', ['id' => $user->id]);

Both constructor arguments are plain values — a DSN (amqp://user:pass@host:port) and an exchange name — so wiring one up through the Injector under your own alias is a one-line factory. AmqpPublisher opens a connection, declares the exchange, publishes, and closes the connection on every call; it does not hold a connection open between calls, so it suits code that publishes occasionally rather than a high-throughput producer.

Testing Code That Publishes

Depend on CommandPublisher, not AmqpPublisher, in the code under test, and swap in RecordingPublisher to assert on what was sent without a broker:

use Sukarix\Messaging\RecordingPublisher;

$publisher = new RecordingPublisher();
$service = new OrderService($publisher);

$service->confirm($order);

$test->expect('order.confirmed' === $publisher->messages[0]['routing_key'], 'the confirmation event was published');

$messages is a plain array of ['routing_key' => ..., 'payload' => ...] entries, in publish order.