From 0f717e2749e0728f88b9bef5bfa4840637f353e4 Mon Sep 17 00:00:00 2001
From: Oliver <oliver.henry.walters@gmail.com>
Date: Tue, 2 Jun 2026 16:16:19 +1000
Subject: [PATCH] Specify R as ohms (#12065)

* Specify R as ohms

* Adjust comments
---
 src/backend/InvenTree/InvenTree/conversion.py |  3 +++
 src/backend/InvenTree/InvenTree/tests.py      | 10 ++++++++++
 2 files changed, 13 insertions(+)

diff --git a/src/backend/InvenTree/InvenTree/conversion.py b/src/backend/InvenTree/InvenTree/conversion.py
index 8db0eb8330..3b6fda27b8 100644
--- a/src/backend/InvenTree/InvenTree/conversion.py
+++ b/src/backend/InvenTree/InvenTree/conversion.py
@@ -114,6 +114,9 @@ def reload_unit_registry():
     reg.define('@alias degF = Fahrenheit')
     reg.define('@alias degK = Kelvin')
 
+    # Override R as ohm (pint defines R as an SI prefix by default)
+    reg.define('R = ohm')
+
     # Define some "standard" additional units
     reg.define('piece = 1')
     reg.define('each = 1 = ea')
diff --git a/src/backend/InvenTree/InvenTree/tests.py b/src/backend/InvenTree/InvenTree/tests.py
index e0977075d5..38062926d5 100644
--- a/src/backend/InvenTree/InvenTree/tests.py
+++ b/src/backend/InvenTree/InvenTree/tests.py
@@ -293,6 +293,16 @@ class ConversionTest(TestCase):
             )
             self.assertAlmostEqual(output, expected, 12)
 
+        # Test that 'R' is interpreted as ohms
+        # Ref: https://github.com/inventree/InvenTree/issues/12063
+        r_tests = [('8R6', 8.6), ('10R', 10), ('4R7', 4.7), ('100R', 100)]
+
+        for val, expected in r_tests:
+            output = InvenTree.conversion.convert_physical_value(
+                val, 'ohm', strip_units=True
+            )
+            self.assertAlmostEqual(output, expected, 6)
+
     def test_scientific_notation(self):
         """Test that scientific notation is handled correctly."""
         tests = [