Testing

After every change you need to make sure that login, checkout and the other scenarios still work. Checking that by hand is slow. Laravel lets you describe a scenario in code: the test sends the request itself and checks the response.

Creating a test

php artisan make:test PostTest

The file appears in tests/Feature. Tests in this folder check the application as a whole: the route, the controller, the database and the template.

Checking a page

namespace Tests\Feature;
 
use Tests\TestCase;
 
class PostTest extends TestCase
{
    public function test_home_page_opens(): void
    {
        $response = $this->get('/');
 
        $response->assertStatus(200);
        $response->assertSee('Welcome');
    }
}

The get() method sends a request inside the application — no real server is needed. The name of a test method starts with test.

Tests with a database

The RefreshDatabase trait creates the tables in a separate test database before the tests and returns it to its initial state after each test. The data is prepared with factories:

use App\Models\Post;
use Illuminate\Foundation\Testing\RefreshDatabase;
 
class PostTest extends TestCase
{
    use RefreshDatabase;
 
    public function test_post_page_shows_title(): void
    {
        $post = Post::factory()->create(['title' => 'First post']);
 
        $this->get("/posts/{$post->id}")
            ->assertOk()
            ->assertSee('First post');
    }
}

Acting as a user

actingAs() runs the request as though the user were already logged in:

public function test_guest_cannot_create_post(): void
{
    $this->post('/posts', ['title' => 'Test'])->assertRedirect('/login');
}
 
public function test_user_can_create_post(): void
{
    $user = User::factory()->create();
 
    $this->actingAs($user)
        ->post('/posts', ['title' => 'Test', 'body' => 'Text'])
        ->assertRedirect('/posts');
 
    $this->assertDatabaseHas('posts', ['title' => 'Test']);
}

assertDatabaseHas() checks that the record really appeared in the table.

Testing validation and an API

public function test_title_is_required(): void
{
    $user = User::factory()->create();
 
    $this->actingAs($user)
        ->post('/posts', ['title' => ''])
        ->assertSessionHasErrors('title');
}
 
public function test_api_returns_posts(): void
{
    Post::factory()->count(3)->create();
 
    $this->getJson('/api/posts')
        ->assertOk()
        ->assertJsonCount(3, 'data');
}

Running

php artisan test
php artisan test --filter=PostTest

The first command runs every test, the second only the given class.

Common mistake

Without RefreshDatabase the tests write to the database and get in each other's way: the second run fails because a record with that email already exists. And make sure the tests use a separate database — it is set in the phpunit.xml file. Otherwise the trait wipes the database you work with.

Thanks for reading!