Laravel Testing

Testing patterns with Pest: Arrange-Act-Assert, proper mocking, null drivers, declarative factories.

Related guides:

• testing-conventions.md - Test file structure and RESTful ordering
• testing-factories.md - Declarative factory methods for readable tests
• validation-testing.md - Form request validation testing
• Actions - Action pattern for unit testing
• Controllers - Controller patterns for feature testing
• DTOs - DTO test factories
• Services - Service layer with null drivers

Philosophy

Testing should be:

• Isolated - Test one thing at a time
• Reliable - Consistent results every time
• Maintainable - Easy to update when code changes
• Fast - Quick feedback loop
• Realistic - Use factories, not hardcoded values

The Triple-A Pattern

Every test should follow the Arrange-Act-Assert pattern:

1. Arrange the World

Set up all the data and dependencies needed using factories:

it('creates an order with items', function () {
    // Arrange: Create the world state
    $user = User::factory()->create();
    $product = Product::factory()->active()->create(['price' => 1000]);

    $data = CreateOrderData::from([
        'customer_email' => '[email protected]',
        'items' => [
            ['product_id' => $product->id, 'quantity' => 2],
        ],
    ]);

    // Act: Perform the operation
    $order = resolve(CreateOrderAction::class)($user, $data);

    // Assert: Verify the results
    expect($order)
        ->toBeInstanceOf(Order::class)
        ->and($order->items)->toHaveCount(1)
        ->and($order->total)->toBe(2000);
});

2. Act on the World

Perform the single operation you're testing:

// ✅ Good - Single, clear action
$order = resolve(CreateOrderAction::class)($user, $data);

// ❌ Bad - Multiple actions mixed with assertions
$order = resolve(CreateOrderAction::class)($user, $data);
expect($order)->toBeInstanceOf(Order::class);
$order->refresh();
expect($order->total)->toBe(2000);

3. Assert on the Results

Verify the outcomes of your action:

// ✅ Good - Clear, focused assertions
expect($order)
    ->toBeInstanceOf(Order::class)
    ->and($order->status)->toBe(OrderStatus::Pending)
    ->and($order->items)->toHaveCount(2);

assertDatabaseHas('orders', [
    'id' => $order->id,
    'user_id' => $user->id,
]);

// ❌ Bad - Testing implementation details
expect($order->getAttribute('status'))->toBe('pending');

Testing Actions

Actions are the heart of your domain logic and should be thoroughly tested in isolation.

Basic Action Test

use App\Actions\Order\CreateOrderAction;
use App\Data\CreateOrderData;
use App\Enums\OrderStatus;
use App\Models\User;
use function Pest\Laravel\assertDatabaseHas;

it('creates an order', function () {
    // Arrange
    $user = User::factory()->create();
    $data = CreateOrderData::testFactory()->make([
        'status' => OrderStatus::Pending,
    ]);

    // Act
    $order = resolve(CreateOrderAction::class)($user, $data);

    // Assert
    expect($order)->toBeInstanceOf(Order::class);
    assertDatabaseHas('orders', [
        'id' => $order->id,
        'user_id' => $user->id,
        'status' => OrderStatus::Pending->value,
    ]);
});

Testing Action Guard Methods

it('throws exception when user has too many pending orders', function () {
    // Arrange
    $user = User::factory()
        ->has(Order::factory()->pending()->count(5))
        ->create();

    $data =