Specify R as ohms (#12065)

* Specify R as ohms

* Adjust comments

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')

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 = [