Updated email test send to show error on failure

- Added test to cover
- Closes #1874

app/Http/Controllers/SettingController.php

@@ -122,8 +122,14 @@ class SettingController extends Controller
     {
         $this->checkPermission('settings-manage');
 
+        try {
             user()->notify(new TestEmail());
             $this->showSuccessNotification(trans('settings.maint_send_test_email_success', ['address' => user()->email]));
+        } catch (\Exception $exception) {
+            $errorMessage = trans('errors.maintenance_test_email_failure') . "\n" . $exception->getMessage();
+            $this->showErrorNotification($errorMessage);
+        }
+
 
         return redirect('/settings/maintenance#image-cleanup')->withInput();
     }

resources/lang/en/errors.php

@@ -96,4 +96,7 @@ return [
     'api_user_no_api_permission' => 'The owner of the used API token does not have permission to make API calls',
     'api_user_token_expired' => 'The authorization token used has expired',
 
+    // Settings & Maintenance
+    'maintenance_test_email_failure' => 'Error thrown when sending a test email:',
+
 ];

tests/TestEmailTest.php

@@ -1,6 +1,7 @@
 <?php namespace Tests;
 
 use BookStack\Notifications\TestEmail;
+use Illuminate\Contracts\Notifications\Dispatcher;
 use Illuminate\Support\Facades\Notification;
 
 class TestEmailTest extends TestCase
@@ -26,6 +27,24 @@ class TestEmailTest extends TestCase
         Notification::assertSentTo($admin, TestEmail::class);
     }
 
+    public function test_send_test_email_failure_displays_error_notification()
+    {
+        $mockDispatcher = $this->mock(Dispatcher::class);
+        $this->app[Dispatcher::class] = $mockDispatcher;
+
+        $exception = new \Exception('A random error occurred when testing an email');
+        $mockDispatcher->shouldReceive('send')->andThrow($exception);
+
+        $admin = $this->getAdmin();
+        $sendReq = $this->actingAs($admin)->post('/settings/maintenance/send-test-email');
+        $sendReq->assertRedirect('/settings/maintenance#image-cleanup');
+        $this->assertSessionHas('error');
+
+        $message = session()->get('error');
+        $this->assertStringContainsString('Error thrown when sending a test email:', $message);
+        $this->assertStringContainsString('A random error occurred when testing an email', $message);
+    }
+
     public function test_send_test_email_requires_settings_manage_permission()
     {
         Notification::fake();