When Should You Use What?

Use unit tests when you want fast, isolated tests for internal logic.

Use feature tests when testing real-world flows through your app that may depend on routing, middleware, or the database.

Unit Tests

• Purpose: Test small, isolated pieces of logic (usually classes or methods).

• Located in: tests/Unit

• How they work: They don’t load the full Laravel framework or handle things like database, routes, middleware, etc.

• Use Case: Testing business logic, helper classes, service classes, etc.

Example:

// tests/Unit/PriceCalculatorTest.php

use Tests\TestCase;

class PriceCalculatorTest extends TestCase
{
    public function test_discount_is_applied_correctly()
    {
        $calculator = new \App\Services\PriceCalculator();
        $result = $calculator->applyDiscount(100, 10); // 10%

        $this->assertEquals(90, $result);
    }
}

Feature Tests

• Purpose: Test the application's full stack (routes, controllers, middleware, database, etc.)

• Located in: tests/Feature

• How they work: They boot the Laravel framework and simulate real user behavior (like submitting forms or visiting pages).

• Use Case: Testing HTTP requests, database interaction, full flow of a feature.

Example

// tests/Feature/UserRegistrationTest.php

use Illuminate\Foundation\Testing\RefreshDatabase;
use Tests\TestCase;

class UserRegistrationTest extends TestCase
{
    use RefreshDatabase;

    public function test_user_can_register()
    {
        $response = $this->post('/register', [
            'name' => 'John Doe',
            'email' => '[email protected]',
            'password' => 'password',
            'password_confirmation' => 'password',
        ]);

        $response->assertRedirect('/home');
        $this->assertDatabaseHas('users', ['email' => '[email protected]']);
    }
}