Make TestMailer proxying

src/Codeception/Lib/Connector/Yii2.php

@@ -15,6 +15,7 @@
 use yii\base\Security;
 use yii\base\UserException;
 use yii\mail\MessageInterface;
+use yii\symfonymailer\Mailer;
 use yii\web\Application;
 use yii\web\ErrorHandler;
 use yii\web\IdentityInterface;
@@ -422,33 +423,20 @@ protected function encodeCookies(
      */
     protected function mockMailer(array $config): array
     {
-        // options that make sense for mailer mock
-        $allowedOptions = [
-            'htmlLayout',
-            'textLayout',
-            'messageConfig',
-            'messageClass',
-            'useFileTransport',
-            'fileTransportPath',
-            'fileTransportCallback',
-            'view',
-            'viewPath',
-        ];
-
         $mailerConfig = [
             'class' => TestMailer::class,
             'callback' => function (MessageInterface $message) {
                 $this->emails[] = $message;
-            }
+            },
+            'mailer' => [
+                'class' => Mailer::class,
+            ]
         ];
 
-        if (isset($config['components']['mailer']) && is_array($config['components']['mailer'])) {
-            foreach ($config['components']['mailer'] as $name => $value) {
-                if (in_array($name, $allowedOptions, true)) {
-                    $mailerConfig[$name] = $value;
-                }
-            }
+        if (isset($config['components']['mailer'])) {
+            $mailerConfig['mailer'] = $config['components']['mailer'];
         }
+
         $config['components']['mailer'] = $mailerConfig;
 
         return $config;

src/Codeception/Lib/Connector/Yii2/TestMailer.php

@@ -1,23 +1,90 @@
 <?php
 namespace Codeception\Lib\Connector\Yii2;
 
+use yii\base\UnknownMethodException;
+use yii\base\UnknownPropertyException;
+use yii\di\Instance;
 use yii\mail\BaseMailer;
+use yii\mail\MailerInterface;
 
 class TestMailer extends BaseMailer
 {
-    public $messageClass = \yii\symfonymailer\Message::class;
-
     /**
      * @var \Closure
      */
     public $callback;
 
+    /**
+     * @var string|array|MailerInterface Mailer config or component to send mail out in the end
+     */
+    public $mailer = 'mailer';
+
+    /**
+     * @inheritdoc
+     * @throws InvalidConfigException
+     */
+    public function init()
+    {
+        parent::init();
+        $this->mailer = Instance::ensure($this->mailer, MailerInterface::class);
+    }
+
+    /**
+     * @param string $name
+     * @param array $params
+     * @return mixed
+     */
+    public function __call($name, $params)
+    {
+        try {
+            return parent::__call($name, $params);
+        } catch (UnknownMethodException $e) {
+            return call_user_func_array([$this->mailer, $name], $params);
+        }
+    }
+
+    /**
+     * @param string $name
+     * @return mixed
+     */
+    public function __get($name)
+    {
+        try {
+            return parent::__get($name);
+        } catch (UnknownPropertyException $e) {
+            return $this->mailer->{$name};
+        }
+    }
+
+    /**
+     * @param string $name
+     * @param mixed $value
+     */
+    public function __set($name, $value)
+    {
+        try {
+            parent::__set($name, $value);
+        } catch (UnknownPropertyException $e) {
+            $this->mailer->{$name} = $value;
+        }
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function compose($view = null, array $params = [])
+    {
+        $message = $this->mailer->compose($view, $params);
+        $message->mailer = $this;
+        return $message;
+    }
+
     protected function sendMessage($message)
     {
         call_user_func($this->callback, $message);
         return true;
     }
-    
+
     protected function saveMessage($message)
     {
         call_user_func($this->callback, $message);