wp-prometheus/tests/Unit/Endpoint/MetricsEndpointTest.php

<?php

declare(strict_types=1);

namespace Magdev\WpPrometheus\Tests\Unit\Endpoint;

use Magdev\WpPrometheus\Endpoint\MetricsEndpoint;
use Magdev\WpPrometheus\Metrics\Collector;
use Magdev\WpPrometheus\Metrics\StorageFactory;
use Magdev\WpPrometheus\Tests\Helpers\GlobalFunctionState;
use Magdev\WpPrometheus\Tests\Unit\TestCase;
use PHPUnit\Framework\Attributes\CoversClass;
use PHPUnit\Framework\Attributes\Test;

#[CoversClass(MetricsEndpoint::class)]
class MetricsEndpointTest extends TestCase
{
    private Collector $collector;
    private MetricsEndpoint $endpoint;

    protected function setUp(): void
    {
        parent::setUp();
        $this->resetStorageFactory();
        $this->collector = new Collector();
        $this->endpoint = new MetricsEndpoint($this->collector);
    }

    protected function tearDown(): void
    {
        $this->resetStorageFactory();
        parent::tearDown();
    }

    // ── Constructor ───────────────────────────────────────────────

    #[Test]
    public function constructor_accepts_collector(): void
    {
        $this->assertInstanceOf(MetricsEndpoint::class, $this->endpoint);
    }

    // ── register_endpoint() ───────────────────────────────────────

    #[Test]
    public function register_endpoint_adds_rewrite_rule(): void
    {
        $this->endpoint->register_endpoint();

        $this->assertSame(1, GlobalFunctionState::getCallCount('add_rewrite_rule'));
        $args = GlobalFunctionState::$callArgs['add_rewrite_rule'][0];
        $this->assertSame('^metrics/?$', $args[0]);
        $this->assertSame('index.php?wp_prometheus_metrics=1', $args[1]);
        $this->assertSame('top', $args[2]);
    }

    #[Test]
    public function register_endpoint_adds_rewrite_tag(): void
    {
        $this->endpoint->register_endpoint();

        $this->assertSame(1, GlobalFunctionState::getCallCount('add_rewrite_tag'));
        $args = GlobalFunctionState::$callArgs['add_rewrite_tag'][0];
        $this->assertSame('%wp_prometheus_metrics%', $args[0]);
        $this->assertSame('([^&]+)', $args[1]);
    }

    // ── handle_request() ──────────────────────────────────────────

    #[Test]
    public function handle_request_returns_early_when_no_query_var(): void
    {
        $wp = new \WP();
        $wp->query_vars = [];

        // Should return without calling exit or outputting anything.
        $this->endpoint->handle_request($wp);

        // If we reach this assertion, handle_request returned early (no exit).
        $this->assertTrue(true);
    }

    #[Test]
    public function handle_request_returns_early_when_query_var_empty(): void
    {
        $wp = new \WP();
        $wp->query_vars = ['wp_prometheus_metrics' => ''];

        $this->endpoint->handle_request($wp);

        $this->assertTrue(true);
    }

    // ── Helpers ──────────────────────────────────────────────────

    private function resetStorageFactory(): void
    {
        $reflection = new \ReflectionClass(StorageFactory::class);
        $property = $reflection->getProperty('instance');
        $property->setValue(null, null);
    }
}