From b985679d6b30b3a983c7b1df5fb23eef0dc95cd3 Mon Sep 17 00:00:00 2001
From: Julius Unverfehrt <julius.unverfehrt@iqser.com>
Date: Thu, 16 Mar 2023 17:27:33 +0100
Subject: [PATCH] add safety mesasure for monitoring in case a service didn't
 find any results.

---
 pyinfra/payload_processing/monitor.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/pyinfra/payload_processing/monitor.py b/pyinfra/payload_processing/monitor.py
index ebcd714..b7f2530 100644
--- a/pyinfra/payload_processing/monitor.py
+++ b/pyinfra/payload_processing/monitor.py
@@ -46,6 +46,9 @@ class PrometheusMonitor:
 
             runtime = time() - start
 
+            if not result:
+                return result
+
             processing_time_per_entity = runtime / len(result)
 
             self.entity_processing_time_sum.observe(processing_time_per_entity)