michaelschiemer/tests/Framework/Metrics/MetricsFormatterTest.php

<?php

declare(strict_types=1);

use App\Framework\Metrics\Formatters\JsonFormatter;
use App\Framework\Metrics\Formatters\OpenMetricsFormatter;
use App\Framework\Metrics\Formatters\PrometheusFormatter;
use App\Framework\Metrics\Formatters\StatsDFormatter;
use App\Framework\Metrics\MetricsCollection;

it('formats metrics in Prometheus format', function () {
    $collection = new MetricsCollection();
    $collection->counter('http_requests_total', 1234, 'Total HTTP requests', ['method' => 'GET', 'status' => '200']);
    $collection->gauge('memory_usage_bytes', 67108864, 'Memory usage in bytes');

    $formatter = new PrometheusFormatter();
    $output = $formatter->format($collection);

    expect($output)->toContain('# HELP http_requests_total Total HTTP requests');
    expect($output)->toContain('# TYPE http_requests_total counter');
    expect($output)->toContain('http_requests_total{method="GET",status="200"} 1234');
    expect($output)->toContain('# HELP memory_usage_bytes Memory usage in bytes');
    expect($output)->toContain('# TYPE memory_usage_bytes gauge');
    expect($output)->toContain('memory_usage_bytes 67108864');
});

it('formats metrics in OpenMetrics format', function () {
    $collection = new MetricsCollection();
    $collection->counter('http_requests_total', 1234, 'Total HTTP requests', ['method' => 'GET']);

    $formatter = new OpenMetricsFormatter();
    $output = $formatter->format($collection);

    expect($output)->toContain('# HELP http_requests_total Total HTTP requests');
    expect($output)->toContain('# TYPE http_requests_total counter');
    expect($output)->toContain('http_requests_total{method="GET"} 1234');
    expect($output)->toContain('# EOF');
});

it('formats metrics in JSON format', function () {
    $collection = new MetricsCollection();
    $collection->counter('requests', 100, 'Request count', ['endpoint' => '/api']);

    $formatter = new JsonFormatter();
    $output = $formatter->format($collection);

    $data = json_decode($output, true);
    expect($data)->toHaveKey('timestamp');
    expect($data)->toHaveKey('metrics');
    expect($data['metrics'])->toHaveCount(1);
    expect($data['metrics'][0])->toMatchArray([
        'name' => 'requests',
        'value' => 100,
        'type' => 'counter',
        'help' => 'Request count',
        'labels' => ['endpoint' => '/api'],
    ]);
});

it('formats metrics in StatsD format', function () {
    $collection = new MetricsCollection();
    $collection->counter('api.requests', 42);
    $collection->gauge('memory.usage', 1024.5, null, ['host' => 'server1']);

    $formatter = new StatsDFormatter();
    $output = $formatter->format($collection);

    $lines = explode("\n", $output);
    expect($lines)->toContain('api.requests:42|c');
    expect($lines)->toContain('memory.usage:1024.5|g|#host:server1');
});

it('handles histogram metrics correctly', function () {
    $collection = new MetricsCollection();
    $collection->histogram(
        'http_request_duration',
        [
            '0.1' => 100,
            '0.5' => 200,
            '1.0' => 250,
            '+Inf' => 300,
        ],
        150.5,
        300,
        'HTTP request duration in seconds'
    );

    $formatter = new PrometheusFormatter();
    $output = $formatter->format($collection);

    expect($output)->toContain('# TYPE http_request_duration histogram');
    expect($output)->toContain('http_request_duration_bucket{le="0.1"} 100');
    expect($output)->toContain('http_request_duration_bucket{le="0.5"} 200');
    expect($output)->toContain('http_request_duration_bucket{le="1.0"} 250');
    expect($output)->toContain('http_request_duration_bucket{le="+Inf"} 300');
    expect($output)->toContain('http_request_duration_sum 150.5');
    expect($output)->toContain('http_request_duration_count 300');
});

it('escapes special characters in labels', function () {
    $collection = new MetricsCollection();
    $collection->counter('test', 1, null, [
        'path' => '/api/test"quotes"',
        'description' => "Line\nbreak",
    ]);

    $formatter = new PrometheusFormatter();
    $output = $formatter->format($collection);

    expect($output)->toContain('path="/api/test\\"quotes\\""');
    expect($output)->toContain('description="Line\\nbreak"');
});

it('converts metrics collection to array', function () {
    $collection = new MetricsCollection();
    $collection->counter('test', 42, 'Test metric', ['env' => 'prod']);

    $array = $collection->toArray();

    expect($array)->toHaveKey('timestamp');
    expect($array)->toHaveKey('metrics');
    expect($array['metrics'])->toHaveCount(1);
    expect($array['metrics'][0])->toMatchArray([
        'name' => 'test',
        'value' => 42,
        'type' => 'counter',
        'help' => 'Test metric',
        'labels' => ['env' => 'prod'],
    ]);
});