Add support for passing transport name

Author: robertpustulka

src/Job/SendMailJob.php

@@ -18,6 +18,7 @@
 
 use Cake\Log\Log;
 use Cake\Mailer\AbstractTransport;
+use Cake\Mailer\TransportFactory;
 use Cake\Queue\Queue\Processor;
 
 /**
@@ -65,12 +66,15 @@ public function execute(Message $message): ?string
      */
     protected function getTransport(string $transportClassName, array $config): AbstractTransport
     {
+        if ($transportClassName === '') {
+            throw new \InvalidArgumentException('Transport class name is empty.');
+        }
+
         if (
-            empty($transportClassName) ||
             !class_exists($transportClassName) ||
             !method_exists($transportClassName, 'send')
         ) {
-            throw new \InvalidArgumentException(sprintf('Transport class name is not valid: %s', $transportClassName));
+            return TransportFactory::get($transportClassName);
         }
 
         $transport = new $transportClassName($config);

tests/TestCase/Job/SendMailJobTest.php

@@ -18,6 +18,7 @@
 
 use Cake\Mailer\Mailer;
 use Cake\Mailer\Transport\DebugTransport;
+use Cake\Mailer\TransportFactory;
 use Cake\Queue\Job\Message;
 use Cake\Queue\Job\SendMailJob;
 use Cake\Queue\Queue\Processor;
@@ -78,6 +79,32 @@ public function testExecute()
         $this->assertSame(Processor::ACK, $actual);
     }
 
+    /**
+     * Test execute method with transport name
+     *
+     * @return void
+     */
+    public function testExecuteTransportName()
+    {
+        $job = new SendMailJob();
+        $message = $this->createMessage('foo', [], $this->message);
+        $emailMessage = new \Cake\Mailer\Message();
+        $data = json_decode($message->getArgument('emailMessage'), true);
+        $emailMessage->createFromArray($data);
+
+        $transport = $this->getMockBuilder(DebugTransport::class)->getMock();
+        $transport->expects($this->once())
+            ->method('send')
+            ->with($emailMessage)
+            ->willReturn(['message' => 'test', 'headers' => []]);
+        TransportFactory::getRegistry()->set('foo', $transport);
+
+        $actual = $job->execute($message);
+        $this->assertSame(Processor::ACK, $actual);
+
+        TransportFactory::drop('foo');
+    }
+
     /**
      * Test execute with attachments method
      *