Object of class App\Mail\EmailGenerator could not be converted to string

Question

I have a Mail fie called EmailGenerator and I have test called NotificationTest.

Everytime I run the tests, I'm always getting this error.

 Object of class App\Mail\EmailGenerator could not be converted to string

Here's my NotificationTest.php

<?php

namespace Tests\Unit;

use Tests\TestCase;
use App\Http\Livewire\Notifications\CreateNotification;
use App\Http\Livewire\Notifications\ManageNotifications;
use App\Models\EmailTemplate;
use Livewire\Livewire;
use Mockery;
use Mockery\MockInterface;
use Mail;
use App\Mail\EmailGenerator;
use App\Models\User;

class NotificationTest extends TestCase
{
    public function test_sample_email()
    {
        Mail::fake();

        Mail::assertNothingSent();
        
        $template = EmailTemplate::factory()->create([
            'name' => 'foo',
        ]);

        Mail::assertSent(new EmailGenerator($template));
    }
}

I just copied the sample code from this documetation https://laravel.com/docs/8.x/mocking#mail-fake

And here's my code in EmailGenerator.php

<?php

namespace App\Mail;

use Illuminate\Bus\Queueable;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Mail\Mailable;
use Illuminate\Queue\SerializesModels;
use App\Models\EmailTemplate;

class EmailGenerator extends Mailable
{
    use Queueable, SerializesModels;

    public $template;

    /**
     * Create a new message instance.
     *
     * @return void
     */
    public function __construct(EmailTemplate $template)
    {
        $this->template = $template;
    }

    /**
     * Build the message.
     *
     * @return $this
     */
    public function build()
    {
        return $this->subject($this->template->subject)
                    ->markdown('emails.generator');
    }
}

Answer 1

Looks like Mail::assertSent is expecting the class name not an instance of the class.

Maybe change to:

Mail::assertSent(EmailGenerator::class, 1);