PHPUnit - Integration & Functional Testing

<?php
declare(strict_types=1);

use PHPUnitFrameworkTestCase;

// ── Integration Test - Service + Real In-Memory Repository ────
class PostServiceIntegrationTest extends TestCase {
    private PostService            $service;
    private InMemoryPostRepository $repo;
    private EventDispatcher        $events;
    private array                  $firedEvents = [];

    protected function setUp(): void {
        $this->repo   = new InMemoryPostRepository();
        $this->events = new EventDispatcher();

        // Record fired events for assertion
        $this->events->listen(PostPublished::class, new class($this->firedEvents) implements EventListenerInterface {
            public function __construct(private array &$events) {}
            public function handle(object $event): void { $this->events[] = $event; }
        });

        $this->service = new PostService($this->repo, $this->events);
    }

    public function test_create_and_immediately_publish(): void {
        $post = $this->service->create([
            "title"     => "Integration Test Post",
            "body"      => "Hello from the test suite.",
            "author_id" => 1,
        ]);

        $this->assertSame("draft", $post->getStatus()->value);

        $published = $this->service->publishPost($post->id);
        $this->assertSame("published", $published->getStatus()->value);
        $this->assertNotNull($published->getPublishedAt());
        $this->assertCount(1, $this->firedEvents);
        $this->assertInstanceOf(PostPublished::class, $this->firedEvents[0]);
    }

    public function test_pagination_returns_correct_slice(): void {
        for ($i = 1; $i <= 15; $i++) {
            $post = $this->service->create(["title" => "Post $i", "body" => "Body", "author_id" => 1]);
            $this->service->publishPost($post->id);
        }

        $page1 = $this->service->listPublished(page: 1, perPage: 10);
        $page2 = $this->service->listPublished(page: 2, perPage: 10);

        $this->assertCount(10, $page1["items"]);
        $this->assertCount(5,  $page2["items"]);
        $this->assertSame(15, $page1["total"]);
        $this->assertSame(2,  $page1["last_page"]);
    }

    public function test_search_returns_only_matching_published(): void {
        $match   = $this->service->create(["title" => "PHP Closures Deep Dive", "body" => "...", "author_id" => 1]);
        $noMatch = $this->service->create(["title" => "JavaScript Promises",    "body" => "...", "author_id" => 1]);
        $this->service->publishPost($match->id);
        $this->service->publishPost($noMatch->id);

        $results = $this->service->listPublished(page: 1, perPage: 10, search: "PHP");
        $this->assertCount(1, $results["items"]);
        $this->assertStringContainsString("PHP", $results["items"][0]->title);
    }
}

// ── Functional Test - HTTP layer via PHP built-in server or mocking ───
class PostControllerFunctionalTest extends TestCase {
    /** @test */
    public function test_post_listing_returns_200_with_json(): void {
        // Functional test without a running server - call the controller directly
        $repo       = new InMemoryPostRepository();
        $service    = new PostService($repo, new NullEventDispatcher());
        $controller = new PostApiController($service, /* auth mock */);

        // Seed data
        $post = $repo->save(new Post(0, "Test", "test", "Body", PostStatus::Published, new Author("Alice", new Email("a@b.com"))));

        // Mock request
        $_SERVER["REQUEST_METHOD"] = "GET";
        $_SERVER["REQUEST_URI"]    = "/api/v1/posts";
        $_GET["page"]              = "1";
        $_GET["per_page"]          = "10";

        $req      = new ApiRequest();
        ob_start();
        $response = $controller->index($req);
        ob_end_clean();

        // Although we can't easily assert HTTP output,
        // we assert on the response object before send()
        $this->assertInstanceOf(ApiResponse::class, $response);
    }
}

// ── Data Provider - test multiple inputs ──────────────────────
class SlugGeneratorTest extends TestCase {
    /** @dataProvider slugInputProvider */
    public function test_generates_correct_slug(string $input, string $expected): void {
        $result = SlugGenerator::from($input);
        $this->assertSame($expected, $result);
    }

    public static function slugInputProvider(): array {
        return [
            "basic"              => ["Hello World",          "hello-world"],
            "with numbers"       => ["PHP 8.2 Features",     "php-8-2-features"],
            "special chars"      => ["C++ vs PHP: A Guide!", "c-vs-php-a-guide"],
            "multiple spaces"    => ["Too  Many   Spaces",   "too-many-spaces"],
            "unicode"            => ["Ünïcödé tïtlé",         "unicode-title"],
            "already slug"       => ["already-a-slug",        "already-a-slug"],
        ];
    }
}