[6.x] Broadcaster - Improve ShouldBroadcastNow performance

[josiasmontag]

Problem

Currently, ShouldBroadcastNow sends the BroadcastEvent to the sync queue. This causes some performance issues:

• It serializes and directly afterwards unserializes the BroadcastEvent
• In combination with the SerializesModels Trait it creates completely unnecessary database queries

Solution

We could just directly dispatchNow() the BroadcastEvent. There should be no reason at all to send it to the the sync queue.

[taylorotwell]

Broadcast manager wasn't being tested so I added some.

[mfn]

Small PSA:

I'm in the process of upgrading and this broke my tests from Laravel 5.8. Previously broadcast events where collected by the QueueFake but now they are dispatched.

In Laravel 5.8 Queue::fake() works because \Illuminate\Broadcasting\BroadcastManager::queue in fact uses the queue:

        $this->app->make('queue')->connection($connection)->push On(
            $queue, new BroadcastEvent(clone $event)
        );

In the above, make('queue') would return the \Illuminate\Support\Testing\Fakes\QueueFake and thus collect the broadcast event and I can assert on that, instead the event gets fired now.

The solution is to now use the Bus::fake() on such tests and use the assertDispatched thereon.

Note: the same break would be true when upgrading from any Laravel version < 6.7

[driesvints]

@mfn good catch. But I think it's best that we leave it as is here.

[mfn]

@driesvints yes! Not suggesting a change, just wanted to make something google-worthy for others 😄