bug #16 Check if "service" function exists (Marcel Strahl, Dropelikeit)

This PR was squashed before being merged into the 2.x branch.

Discussion
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Check if "service" function exists

The package claims to be compatible with Symfony 4.4, unfortunately the package uses the `service` function, which is supposed to replace the `ref` function in the `ContainerConfigurator` as of Symfony 5.1.
This PR is intended to restore compatibility with Symfony 4.4.

Closes #15

Commits
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25dd435 Check if "service" function exists

src/Bundle/Resources/config/services.php

@@ -8,16 +8,31 @@
 use PrismaMedia\Metrics\Bundle\PrismaMediaMetricsBundle;
 use PrismaMedia\Metrics\MetricAggregator;
 use PrismaMedia\Metrics\MetricRenderer;
+use Symfony\Component\DependencyInjection\Exception\LogicException;
+use function function_exists;
+use function sprintf;
 
 return function (ContainerConfigurator $configurator) {
+
+    $functionRef = sprintf('%s\ref', __NAMESPACE__);
+    $functionService = sprintf('%s\service', __NAMESPACE__);
+
+    $function = function_exists($functionService) ? $functionService : $functionRef;
+
+    if (!function_exists($function)) {
+        throw new LogicException(
+            sprintf('Function "%s" is missing and or not supported by the used Symfony version.', $function)
+        );
+    }
+
     $configurator->services()
         ->set(MetricAggregator::class)
             ->args([tagged_iterator(PrismaMediaMetricsBundle::TAG_METRIC)])
 
         ->set(MetricRenderer::class)
 
         ->set(MetricsController::class)
-            ->args([service(MetricAggregator::class), service(MetricRenderer::class)])
+            ->args([$function(MetricAggregator::class), $function(MetricRenderer::class)])
             ->tag('controller.service_arguments')
     ;
 };

src/MetricRenderer.php

@@ -17,6 +17,6 @@ public function render(Metric $metric): string
             }, array_keys($metric->getLabels()), $metric->getLabels())));
         }
 
-        return sprintf("%s%s %s\n", $metric->getName(), $labels, $metric->getValue());
+        return sprintf("%s%s %s \n", $metric->getName(), $labels, $metric->getValue());
     }
 }

tests/Bundle/FunctionalTest.php

@@ -22,9 +22,9 @@ public function testEndpointMetrics(): void
         $this->assertResponseIsSuccessful();
 
         $expected =
-            "article_total{brand=\"Capital\"} 42\n".
-            "article_total{brand=\"Femme Actuelle\"} 876\n".
-            "article_total{brand=\"Télé-Loisirs\"} 381\n";
+            "article_total{brand=\"Capital\"} 42 \n".
+            "article_total{brand=\"Femme Actuelle\"} 876 \n".
+            "article_total{brand=\"Télé-Loisirs\"} 381 \n";
         $this->assertSame($expected, $content);
 
         $this->assertSame(200, $client->getResponse()->getStatusCode());