Output console error when terminating due to memory usage (#1391)

* Show error in console when php artisan:horizon terminates when using more than configured memory

* Update HorizonCommand.php

---------

Co-authored-by: Taylor Otwell <taylor@laravel.com>

src/Listeners/MonitorMasterSupervisorMemory.php

@@ -17,9 +17,13 @@ public function handle(MasterSupervisorLooped $event)
     {
         $master = $event->master;
 
-        if ($master->memoryUsage() > config('horizon.memory_limit', 64)) {
+        $memoryLimit = config('horizon.memory_limit', 64);
+
+        if ($master->memoryUsage() > $memoryLimit) {
             event(new MasterSupervisorOutOfMemory($master));
 
+            $master->output('error', 'Memory limit exceeded: Using '.ceil($master->memoryUsage()).'/'.$memoryLimit.'MB. Consider increasing horizon.memory_limit.');
+
             $master->terminate(12);
         }
     }

tests/Feature/MonitorMasterSupervisorMemoryTest.php

@@ -17,6 +17,7 @@ public function test_supervisor_is_terminated_when_using_too_much_memory()
         $master = Mockery::mock(MasterSupervisor::class);
 
         $master->shouldReceive('memoryUsage')->andReturn(192);
+        $master->shouldReceive('output')->once()->with('error', 'Memory limit exceeded: Using 192/64MB. Consider increasing horizon.memory_limit.');
         $master->shouldReceive('terminate')->once()->with(12);
 
         $monitor->handle(new MasterSupervisorLooped($master));