Testing intro

Front-end folks already know Jest/Vitest. PHP's defaults are PHPUnit (classic) and Pest (nicer syntax on top of PHPUnit). One feature test on the router is enough to get the idea.

PHPUnit vs Pest

	PHPUnit	Pest
Style	Classes + $this->assertSame	it('...', function () { expect(...) })
Base	Itself	PHPUnit under the hood
Laravel	Built-in support	Very popular
Symfony	Common	Also fine

Either is fine. Pest feels closer to Vitest/Jest. PHPUnit shows up everywhere in older codebases.

What to test first

For our mini router: given a method + path, do we get the right status and body fragment?

<?php

declare(strict_types=1);

use App\Router;
use App\Response;
use PHPUnit\Framework\TestCase;

final class RouterTest extends TestCase
{
    public function test_ping_returns_json(): void
    {
        $router = new Router();
        $router->get('/api/ping', fn (): Response => Response::json(['ok' => true]));

        $response = $router->dispatch('GET', '/api/ping');

        $this->assertSame(200, $response->status());
        $this->assertStringContainsString('application/json', $response->headers()['Content-Type'] ?? '');
        $this->assertStringContainsString('"ok":true', $response->body());
    }
}

Pest flavor of the same idea:

<?php

it('pings', function () {
    $router = new Router();
    $router->get('/api/ping', fn () => Response::json(['ok' => true]));

    $response = $router->dispatch('GET', '/api/ping');

    expect($response->status())->toBe(200)
        ->and($response->body())->toContain('"ok":true');
});

Run the example tests

cd examples/http-router
composer install
composer test

That wires PHPUnit via Composer's require-dev and a tiny test suite.

Testing pyramid (PHP web)

1. Unit - pure functions, value objects, routers
2. Feature / Integration - HTTP kernel in-process (Laravel get('/...'), Symfony BrowserKit)
3. Browser - Playwright/Dusk - same as front-end E2E

You already know layer 3. Frameworks make layer 2 pleasant. Layer 1 works with plain PHPUnit today.

Habits that transfer

• Arrange / Act / Assert
• Deterministic tests (no real network / clock when avoidable)
• Test behavior at boundaries (router, parser, money math)
• Don't test the framework itself - test your wiring

When Laravel docs say php artisan test or Symfony says php bin/phpunit, it's this same muscle.

Best,

-- ł.