Add metadata to mailable view data

src/Illuminate/Mail/Mailable.php

@@ -352,7 +352,19 @@ public function buildViewData()
             }
         }
 
-        return $data;
+        return array_merge($data, $this->additionalMessageData());
+    }
+
+    /**
+     * Get additional meta-data to pass along with the view data.
+     *
+     * @return array<string, mixed>
+     */
+    protected function additionalMessageData(): array
+    {
+        return [
+            '__laravel_mailable' => get_class($this),
+        ];
     }
 
     /**

tests/Mail/MailMailableDataTest.php

@@ -9,9 +9,13 @@ class MailMailableDataTest extends TestCase
 {
     public function testMailableDataIsNotLost()
     {
-        $testData = ['first_name' => 'James'];
-
         $mailable = new MailableStub;
+
+        $testData = [
+            'first_name' => 'James',
+            '__laravel_mailable' => get_class($mailable),
+        ];
+
         $mailable->build(function ($m) use ($testData) {
             $m->view('view', $testData);
         });

tests/Mail/MailMailableTest.php

@@ -592,6 +592,7 @@ public function testMailableBuildsViewData()
             'first_name' => 'Taylor',
             'lastName' => 'Otwell',
             'framework' => 'Laravel',
+            '__laravel_mailable' => get_class($mailable),
         ];
 
         $this->assertSame($expected, $mailable->buildViewData());