FIX TestMailer instantiation

src/Context/EmailContext.php

@@ -10,7 +10,9 @@
 use SilverStripe\BehatExtension\Utility\TestMailer;
 use SilverStripe\Core\Injector\Injector;
 use Symfony\Component\DomCrawler\Crawler;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use Symfony\Component\Mailer\MailerInterface;
+use Symfony\Component\Mailer\Transport\NullTransport;
 
 /**
  * Context used to define steps related to email sending.
@@ -48,7 +50,9 @@ public function before(BeforeScenarioScope $event)
     {
         // Also set through the 'supportbehat' extension
         // to ensure its available both in CLI execution and the tested browser session
-        $this->mailer = new TestMailer();
+        $dispatcher = Injector::inst()->get(EventDispatcherInterface::class . '.mailer');
+        $transport = new NullTransport($dispatcher);
+        $this->mailer = new TestMailer($transport, $dispatcher);
         Injector::inst()->registerService($this->mailer, MailerInterface::class);
     }
 

src/Utility/TestMailer.php

@@ -2,8 +2,11 @@
 
 namespace SilverStripe\BehatExtension\Utility;
 
+use Psr\EventDispatcher\EventDispatcherInterface;
 use SilverStripe\Dev\TestMailer as BaseTestMailer;
 use SilverStripe\TestSession\TestSessionEnvironment;
+use Symfony\Component\Mailer\MailerInterface;
+use Symfony\Component\Mailer\Transport\TransportInterface;
 
 /**
  * Same principle as core TestMailer class,
@@ -17,8 +20,11 @@ class TestMailer extends BaseTestMailer
      */
     protected $testSessionEnvironment;
 
-    public function __construct()
-    {
+    public function __construct(
+        TransportInterface $transport,
+        EventDispatcherInterface $dispatcher
+    ) {
+        parent::__construct($transport, $dispatcher);
         $this->testSessionEnvironment = TestSessionEnvironment::singleton();
     }