PHPUnit

When to Use

• Writing or refactoring PHPUnit-style tests in Laravel codebases.
• Maintaining existing class-based test suites alongside Pest-based files.
• Creating focused unit tests for pure PHP logic and feature tests for HTTP/database flows.

When Not to Use

• Browser/E2E flows requiring JavaScript execution (use Dusk).
• New tests in a code area that is standardized on Pest syntax only.
• Integration scenarios where external systems should be faked/stubbed at a higher level.

Preconditions

• phpunit.xml / phpunit.xml.dist is present and configured for this project.
• Test database configuration is isolated from development data.
• Factories exist (or are added) for models under test.
• Team conventions for Pest vs PHPUnit style are known for the touched test area.

Process Checklist

• Pick the right test type: unit (tests/Unit) vs feature (tests/Feature).
• Use RefreshDatabase in feature tests that modify/query DB state.
• Keep one assertion concern per test method.
• Use strict assertions (assertSame) when type and value matter.
• Use model factories and states; avoid manual low-level inserts.
• Run targeted tests first, then full impacted suite.

Rules

• Feature tests extend Tests\TestCase; unit tests extend PHPUnit\Framework\TestCase.
• Use test_ snake_case method names and : void return types.
• Keep tests deterministic and specific in assertions.
• Favor factories/states over hand-crafted persistence setup.

Examples

// Feature test
use Illuminate\Foundation\Testing\RefreshDatabase;
use Tests\TestCase;

class InvoiceControllerTest extends TestCase
{
    use RefreshDatabase;

    public function test_user_can_create_invoice(): void
    {
        $user  = User::factory()->create();
        $order = Order::factory()->create(['user_id' => $user->id]);

        $response = $this->actingAs($user)
            ->postJson('/api/invoices', ['order_id' => $order->id]);

        $response->assertStatus(201);
        $this->assertDatabaseHas('invoices', ['order_id' => $order->id]);
    }
}

// Unit test — no Laravel bootstrap
use PHPUnit\Framework\TestCase;

class MoneyHelperTest extends TestCase
{
    public function test_formats_amount_in_cents_as_currency_string(): void
    {
        $result = MoneyHelper::format(1000, 'CHF');

        $this->assertSame('10.00 CHF', $result);
    }
}

// Factory with states
// database/factories/UserFactory.php
public function unverified(): static
{
    return $this->state(fn (array $attributes) => [
        'email_verified_at' => null,
    ]);
}

// Usage in tests
User::factory()->create();
User::factory()->unverified()->create();

Run Commands

# Full Laravel test run (recommended entrypoint)
php artisan test

# Run PHPUnit directly
vendor/bin/phpunit

# Run a single file
vendor/bin/phpunit tests/Feature/InvoiceControllerTest.php

# Filter by test method name
vendor/bin/phpunit --filter=test_user_can_create_invoice

Testing Guidance

• Run the smallest relevant subset while iterating, then run full impacted suites.
• Keep test naming aligned with behavior, not implementation details.
• Prefer explicit assertions for DB rows, response structure, and domain outputs.

Anti-Patterns

• Not using RefreshDatabase in feature tests that write to the database
• Using raw insert() or create() calls in tests instead of factories
• Mixing multiple assertion concerns in a single test method
• Using assertEquals when assertSame is needed for strict comparison
• Asserting truthiness (assertTrue($result !== null)) instead of a specific value
• Unit tests that bootstrap the full Laravel application (use Tests\TestCase only for feature tests)

References

• PHPUnit Documentation
• Laravel Testing
• Related: PestTesting/SKILL.md — the preferred test framework (Pest over raw PHPUnit)