TDD: LogicException: App\Models\Project::path must return a relationship instance.

I'm at this lesson https://laracasts.com/series/build-a-laravel-app-with-tdd/episodes/14 minute 18:16

when i launch this test i get a different error than the course one

   public function test_a_user_can_create_a_project()
    {

        $this->withoutExceptionHandling();

        $this->singIn();

        $this->get('/projects/create')->assertStatus(200);

        $attributes = [
            'title' => $this->faker->sentence,
            'description' => $this->faker->paragraph,
        ];

        $response = $this->post('/projects', $attributes);

        $project = Project::where($attributes)->first();

        $response->assertRedirect($project->path);

        $this->assertDatabaseHas('projects',$attributes);

        $this->get('/projects')->assertSee($attributes['title']);
    }

gives me following errors:

1. Tests\Feature\ManageProjectsTest::test_a_user_can_create_a_project LogicException: App\Models\Project::path must return a relationship instance.