[12.x] Add hasMailer method to the mailable class (#56340)

* Add the hasMailer class to the Mailable object.

* Set the $currentMailer of MailFake to be the default driver when initialising.

* formatting

---------

Co-authored-by: Taylor Otwell <[email protected]>

Author: kevinb1989

src/Illuminate/Mail/Mailable.php

@@ -1811,6 +1811,17 @@ private function ensureAttachmentsAreHydrated()
             });
     }
 
+    /**
+     * Determine if the mailable will be sent by the given mailer.
+     *
+     * @param  string  $mailer
+     * @return bool
+     */
+    public function usesMailer($mailer)
+    {
+        return $this->mailer === $mailer;
+    }
+
     /**
      * Set the name of the mailer that should send the message.
      *

src/Illuminate/Support/Testing/Fakes/MailFake.php

@@ -55,6 +55,7 @@ class MailFake implements Factory, Fake, Mailer, MailQueue
     public function __construct(MailManager $manager)
     {
         $this->manager = $manager;
+        $this->currentMailer = $manager->getDefaultDriver();
     }
 
     /**

tests/Mail/MailMailableTest.php

@@ -573,10 +573,11 @@ public function testMailerMayBeSet()
         $mailable = new WelcomeMailableStub;
 
         $mailable->mailer('array');
+        $this->assertTrue($mailable->usesMailer('array'));
 
-        $mailable = unserialize(serialize($mailable));
-
-        $this->assertSame('array', $mailable->mailer);
+        $mailable->mailer('smtp');
+        $this->assertTrue($mailable->usesMailer('smtp'));
+        $this->assertFalse($mailable->usesMailer('ses'));
     }
 
     public function testMailablePriorityGetsSent()

tests/Support/SupportTestingMailFakeTest.php

@@ -31,7 +31,10 @@ class SupportTestingMailFakeTest extends TestCase
     protected function setUp(): void
     {
         parent::setUp();
-        $this->mailManager = m::mock(MailManager::class);
+        $this->mailManager = m::mock(MailManager::class, function ($mock) {
+            $mock->shouldReceive('getDefaultDriver')
+                ->andReturn('smtp');
+        });
         $this->fake = new MailFake($this->mailManager);
         $this->mailable = new MailableStub;
     }
@@ -380,6 +383,33 @@ public function testMissingMethodsAreForwarded()
 
         $this->assertEquals('bar', $this->fake->foo());
     }
+
+    public function testAssertMailer()
+    {
+        $this->fake->to('[email protected]')->send($this->mailable);
+
+        $this->fake->assertSent(MailableStub::class, function ($mail) {
+            return $mail->usesMailer('smtp');
+        });
+
+        $this->fake->mailer('ses')->to('[email protected]')->send($this->mailable);
+
+        $this->fake->assertSent(MailableStub::class, function ($mail) {
+            return $mail->usesMailer('ses');
+        });
+
+        $this->fake->mailer('sendgrid')->to('[email protected]')->queue($this->mailable);
+
+        $this->fake->assertQueued(MailableStub::class, function ($mail) {
+            return $mail->usesMailer('sendgrid');
+        });
+
+        $this->fake->mailer('mailjet')->to('[email protected]')->queue($this->mailable);
+
+        $this->fake->assertQueued(MailableStub::class, function ($mail) {
+            return $mail->usesMailer('mailjet');
+        });
+    }
 }
 
 class MailableStub extends Mailable