More unit test tweaks

src/backend/InvenTree/report/templatetags/report.py

@@ -343,7 +343,10 @@ def parameter(
     Returns:
         A Parameter object, or None if not found
     """
-    if not hasattr(instance, 'parameters'):
+    if instance is None:
+        raise ValueError('parameter tag requires a valid Model instance')
+
+    if not isinstance(instance, Model) or not hasattr(instance, 'parameters'):
         raise TypeError("parameter tag requires a Model with 'parameters' attribute")
 
     return (
@@ -354,7 +357,7 @@ def parameter(
 
 
 @register.simple_tag()
-def part_parametr(instance, parameter_name):
+def part_parameter(instance, parameter_name):
     """Included for backwards compatibility - use 'parameter' tag instead.
 
     Ref: https://github.com/inventree/InvenTree/pull/10699

src/backend/InvenTree/report/test_tags.py

@@ -419,8 +419,14 @@ class ReportTagTest(PartImageTestMixin, InvenTreeTestCase):
         # Note, use the 'parameter' and 'part_parameter' tags interchangeably here
         self.assertEqual(report_tags.part_parameter(part, 'name'), None)
         self.assertEqual(report_tags.parameter(part, 'Template 1'), parameter)
-        # Test with an invalid part
+
-        self.assertEqual(report_tags.parameter(None, 'name'), None)
+        # Test with a null part
+        with self.assertRaises(ValueError):
+            report_tags.parameter(None, 'name')
+
+        # Test with an invalid model type
+        with self.assertRaises(TypeError):
+            report_tags.parameter(parameter, 'name')
 
     def test_render_currency(self):
         """Test the render_currency template tag."""