From 2e4c849b2f93ba21a18394400b2cfeb0e52aa661 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Erdem=20K=C3=B6se?= <erdemkose@gmail.com>
Date: Wed, 18 May 2022 04:10:08 +0200
Subject: [PATCH] Allow custom counters implementing CounterInterface to be
 exported (#676)
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Signed-off-by: Erdem Köse <erdemkose@gmail.com>
---
 src/Contrib/Prometheus/PrometheusExporter.php | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/Contrib/Prometheus/PrometheusExporter.php b/src/Contrib/Prometheus/PrometheusExporter.php
index 7c30912cb..89c4a3f78 100644
--- a/src/Contrib/Prometheus/PrometheusExporter.php
+++ b/src/Contrib/Prometheus/PrometheusExporter.php
@@ -5,7 +5,6 @@
 namespace OpenTelemetry\Contrib\Prometheus;
 
 use OpenTelemetry\API\Metrics as API;
-use OpenTelemetry\SDK\Metrics\Counter;
 use OpenTelemetry\SDK\Metrics\Exceptions\CantBeExported;
 use OpenTelemetry\SDK\Metrics\Exporters\AbstractExporter;
 use Prometheus\CollectorRegistry;
@@ -28,8 +27,8 @@ public function __construct(CollectorRegistry $registry, string $namespace = '')
     protected function doExport(iterable $metrics): void
     {
         foreach ($metrics as $metric) {
-            switch (get_class($metric)) {
-                case Counter::class:
+            switch (true) {
+                case $metric instanceof API\CounterInterface:
                     $this->exportCounter($metric);
 
                     break;