How do I run a phpunit test on Redis pub/sub? - laravel

Question

I'm building a messenger system with Redis publishing on the Laravel end and subscribing on a node server. I would like to test what is stored in the redis pub method using PHPUnit, but I have no idea where to start.
Controller
class MessageController extends Controller
{
public function store(Conversation $conversation, Request $request)
{
$user = Auth::user();
$message = Message::create([
'body' => $request->input('message'),
'conversation_id' => $conversation->id,
'sender_id' => $user->id,
'type' => 'user_message'
]);
$redis = Redis::connection();
$data = new MessageResource($message);
$redis->publish('message', $data);
}
}
Current Test
/** #test */
public function a_user_can_send_a_message()
{
$this->actingAs($user = User::factory()->create());
$message = Message::factory()->make(['sender_id' => $user->id]);
$conversation Conversation::factory()->create();
$response = $this->json('POST', '/api/message/'. $conversation->id, ['message' => $message->body])
->assertStatus(201);
$response->assertJsonStructure([
'data' => [
'body',
'sender',
]
]);
}
Essentially what I'm trying to see is if message has been published on Redis. I'm unsure how to do this, and I think you would probably need to clear the message from Redis after, would you not?

Answer 1

Your test should be like this:
public function test_a_user_can_send_a_message()
{
$redisSpy = Redis::spy();
$redisSpy->shouldReceive('connection')->andReturnSelf();
$this->actingAs($user = User::factory()->create());
$message = Message::factory()->make(['sender_id' => $user->id]);
$conversation = Conversation::factory()->create();
$this->postJson("/api/message/{$conversation->id}", ['message' => $message->body]);
$this->assertDatabaseCount('messages', 1);
$redisSpy->shouldHaveReceived('publish')
->with('message', new MessageResource(Message::first()));
}
As you can see, I have added Redis::spy(); this is going to allow is to "spy" what is called from Redis. You can still mock methods, and we have to do so, because you use Redis::connect(); and then $redis->publish(...), so we will return the spy when connect is called, that is why we do shouldReceive('connection')->andReturnSelf().
At the end of the code, we check that $redis->publish was called with parameters 'message' and a resource with the desired message. Both must match for this assertion to pass, else you will see a mock error.