Laravel Testing: Beyond the Basics

by

 

Published: November 2025
Author: Chris Beaver
Category: Development, PHP, Laravel

Testing is one of those things every developer knows they should do, but many struggle to do well. Over the past decade of Laravel development, I’ve learned that the difference between tests that help and tests that hurt usually comes down to a few key principles.

The Problem With Bad Tests

I’ve seen (and written) plenty of bad tests. Tests that break when you change unrelated code. Tests that pass when the feature is broken. Tests that take forever to run. Tests so complicated you need tests for your tests.

Bad tests are worse than no tests because they give false confidence while slowing down development.

What Makes Tests Actually Useful

Good tests have a few characteristics:

They’re Fast
If your test suite takes 10 minutes to run, you won’t run it. Fast tests mean you catch problems immediately instead of after you’ve moved on to three other things.

They’re Isolated
Each test should be independent. Running tests in parallel shouldn’t cause random failures. This means properly managing database state, clearing caches, and avoiding shared state between tests.

They Test Behavior, Not Implementation
Tests should verify that your application does what it’s supposed to do, not that it does it a specific way. When you refactor code, tests should still pass if behavior hasn’t changed.

They’re Readable
Six months from now, when a test fails, you should be able to quickly understand what it’s testing and why it’s failing. Clear test names and straightforward assertions matter.

Parallel Testing in Laravel

Laravel’s parallel testing support is a game-changer for test suite speed, but it requires some setup discipline.

The key insight: parallel tests run in separate processes with separate databases. This means:

  1. Each test must be truly independent
  2. Database transactions work great for isolation
  3. Shared state (caches, files, external services) needs careful handling

Here’s what I’ve learned about making parallel testing work reliably:

Use Database Transactions

Laravel’s RefreshDatabase trait with database transactions is your friend. Each test runs in a transaction that gets rolled back, leaving the database clean for the next test.

use Illuminate\Foundation\Testing\RefreshDatabase;

class UserTest extends TestCase
{
    use RefreshDatabase;

    public function test_user_can_register()
    {
        // Database changes are rolled back after this test
        $response = $this->post('/register', [
            'name' => 'Chris',
            'email' => '[email protected]',
            'password' => 'password123'
        ]);

        $response->assertStatus(302);
        $this->assertDatabaseHas('users', [
            'email' => '[email protected]'
        ]);
    }
}

Watch Out for Shared Resources

Caches, file systems, and external API calls can cause race conditions in parallel tests. Either mock them or ensure each test uses unique identifiers.

Keep Tests Focused

One test should verify one behavior. This makes failures obvious and tests faster.

Testing Different Layers

Not all tests are created equal. I think about testing in layers:

Unit Tests
Test individual classes or methods in isolation. Mock dependencies. These should be lightning fast.

Feature Tests
Test complete features from HTTP request to response. These verify that all your pieces work together.

Integration Tests
Test how your application interacts with external services. These are slower but catch issues that unit tests miss.

Most of your tests should be unit tests. Feature tests verify the happy paths and key edge cases. Integration tests prove that your assumptions about external services are correct.

The Real Value of Testing

Here’s what good tests actually give you:

Confidence to Change Code
Refactoring without tests is terrifying. With tests, you can improve code structure knowing you’ll catch any breakage.

Documentation That Doesn’t Lie
Comments go stale. Tests that pass prove how the system actually works right now.

Better Architecture
Code that’s hard to test is usually badly structured. Testing forces you to write more modular, decoupled code.

Faster Development
This sounds counterintuitive, but automated tests are faster than manual testing. Once you have good test coverage, you catch bugs in seconds instead of minutes or hours of clicking around.

When Not to Test

Not everything needs comprehensive test coverage:

  • Configuration files
  • Simple getters/setters
  • Framework code (Laravel is already tested)
  • Obvious code where the test would be longer than the implementation

Test the code that matters: business logic, edge cases, integrations, anything that could break in ways that hurt users.

Making Testing a Habit

The best time to write tests is while you’re writing the feature. Not after. Not next sprint. Now.

Test-driven development (TDD) can feel slow at first, but it’s actually faster once you get used to it. You spend less time debugging because you catch issues immediately.

Wrapping Up

Good testing isn’t about hitting coverage percentages. It’s about having confidence that your application works correctly and will keep working as you change it.

Start small. Add tests for new features. When you fix bugs, write tests that would have caught them. Over time, you’ll build up coverage where it matters.

The goal isn’t perfect tests. The goal is useful tests that make development faster and more reliable.

Building Laravel applications with comprehensive test coverage is one of our core services. If you’re struggling with testing strategy or need help improving an existing codebase, let’s talk.

Leave a Comment