wp-prometheus/tests/Unit/Metrics/CollectorTest.php

<?php

declare(strict_types=1);

namespace Magdev\WpPrometheus\Tests\Unit\Metrics;

use Magdev\WpPrometheus\Metrics\Collector;
use Magdev\WpPrometheus\Metrics\RuntimeCollector;
use Magdev\WpPrometheus\Metrics\StorageFactory;
use Magdev\WpPrometheus\Tests\Unit\TestCase;
use PHPUnit\Framework\Attributes\CoversClass;
use PHPUnit\Framework\Attributes\Test;
use Prometheus\CollectorRegistry;
use Prometheus\Counter;
use Prometheus\Gauge;
use Prometheus\Histogram;

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

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

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

    // ── Constructor & Basic Properties ─────────────────────────────

    #[Test]
    public function constructor_creates_registry(): void
    {
        $this->assertInstanceOf(CollectorRegistry::class, $this->collector->get_registry());
    }

    #[Test]
    public function get_namespace_returns_wordpress(): void
    {
        $this->assertSame('wordpress', $this->collector->get_namespace());
    }

    // ── register_gauge() ──────────────────────────────────────────

    #[Test]
    public function register_gauge_returns_gauge_instance(): void
    {
        $gauge = $this->collector->register_gauge('test_metric', 'A test gauge');
        $this->assertInstanceOf(Gauge::class, $gauge);
    }

    #[Test]
    public function register_gauge_with_labels(): void
    {
        $gauge = $this->collector->register_gauge(
            'labeled_metric',
            'A labeled gauge',
            ['label1', 'label2']
        );
        $this->assertInstanceOf(Gauge::class, $gauge);
    }

    // ── register_counter() ────────────────────────────────────────

    #[Test]
    public function register_counter_returns_counter_instance(): void
    {
        $counter = $this->collector->register_counter('test_counter', 'A test counter');
        $this->assertInstanceOf(Counter::class, $counter);
    }

    #[Test]
    public function register_counter_with_labels(): void
    {
        $counter = $this->collector->register_counter(
            'labeled_counter',
            'A labeled counter',
            ['method', 'status']
        );
        $this->assertInstanceOf(Counter::class, $counter);
    }

    // ── register_histogram() ──────────────────────────────────────

    #[Test]
    public function register_histogram_returns_histogram_instance(): void
    {
        $histogram = $this->collector->register_histogram('test_histogram', 'A test histogram');
        $this->assertInstanceOf(Histogram::class, $histogram);
    }

    #[Test]
    public function register_histogram_with_custom_buckets(): void
    {
        $buckets = [0.1, 0.5, 1.0, 5.0];
        $histogram = $this->collector->register_histogram(
            'custom_buckets_hist',
            'A histogram with custom buckets',
            ['label1'],
            $buckets
        );
        $this->assertInstanceOf(Histogram::class, $histogram);
    }

    // ── render() ──────────────────────────────────────────────────

    #[Test]
    public function render_returns_string(): void
    {
        $getOption = $this->getFunctionMock('Magdev\\WpPrometheus\\Metrics', 'get_option');
        $getOption->expects($this->any())->willReturn([]);

        $output = $this->collector->render();
        $this->assertIsString($output);
    }

    #[Test]
    public function render_includes_registered_gauge_value(): void
    {
        $getOption = $this->getFunctionMock('Magdev\\WpPrometheus\\Metrics', 'get_option');
        $getOption->expects($this->any())->willReturn([]);

        $gauge = $this->collector->register_gauge('test_render_metric', 'Test metric for render');
        $gauge->set(42, []);

        $output = $this->collector->render();

        $this->assertStringContainsString('wordpress_test_render_metric', $output);
        $this->assertStringContainsString('42', $output);
    }

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

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

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