From 2e27e6622482886babbeb9e9918e3be95634381a Mon Sep 17 00:00:00 2001
From: Marc-Olivier Arsenault <marcolivier.arsenault@gmail.com>
Date: Mon, 4 Dec 2023 20:37:20 -0500
Subject: [PATCH] add protection for dividing by zero (#240)

---
 custom_components/moonraker/sensor.py |  3 +++
 tests/test_sensor.py                  | 29 +++++++++++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/custom_components/moonraker/sensor.py b/custom_components/moonraker/sensor.py
index ad0e566..63a2f13 100755
--- a/custom_components/moonraker/sensor.py
+++ b/custom_components/moonraker/sensor.py
@@ -571,6 +571,9 @@ def calculate_current_layer(data):
     ):
         return data["status"]["print_stats"]["info"]["current_layer"]
 
+    if "layer_height" not in data or data["layer_height"] <= 0:
+        return 0
+
     # layer = (current_z - first_layer_height) / layer_height + 1
     return (
         int(
diff --git a/tests/test_sensor.py b/tests/test_sensor.py
index c615450..d1d4b68 100755
--- a/tests/test_sensor.py
+++ b/tests/test_sensor.py
@@ -338,6 +338,35 @@ async def test_current_layer_calculated():
     assert calculate_current_layer(data) == 42
 
 
+async def test_current_layer_calculated_layer_height_0():
+    data = {
+        "status": {
+            "print_stats": {
+                "state": PRINTSTATES.PRINTING.value,
+                "filename": "TheUniverse.gcode",
+            },
+            "toolhead": {"position": [0, 0, 8.4]},
+        },
+        "first_layer_height": 0.2,
+        "layer_height": 0,
+    }
+    assert calculate_current_layer(data) == 0
+
+
+async def test_current_layer_calculate_missing_layer_height():
+    data = {
+        "status": {
+            "print_stats": {
+                "state": PRINTSTATES.PRINTING.value,
+                "filename": "TheUniverse.gcode",
+            },
+            "toolhead": {"position": [0, 0, 8.4]},
+        },
+        "first_layer_height": 0.2,
+    }
+    assert calculate_current_layer(data) == 0
+
+
 async def test_current_layer_calculated_partial_info():
     data = {
         "status": {