Consolidate CableCSVForm validation logic

netbox/dcim/forms.py

@@ -3810,58 +3810,36 @@ class CableCSVForm(CSVModelForm):
             'color': mark_safe('RGB color in hexadecimal (e.g. <code>00ff00</code>)'),
         }
 
-    # TODO: Merge the clean() methods for either end
-    def clean_side_a_name(self):
+    def _clean_side(self, side):
+        """
+        Derive a Cable's A/B termination objects.
+
+        :param side: 'a' or 'b'
+        """
+        assert side in 'ab', f"Invalid side designation: {side}"
 
-        device = self.cleaned_data.get('side_a_device')
-        content_type = self.cleaned_data.get('side_a_type')
-        name = self.cleaned_data.get('side_a_name')
+        device = self.cleaned_data.get(f'side_{side}_device')
+        content_type = self.cleaned_data.get(f'side_{side}_type')
+        name = self.cleaned_data.get(f'side_{side}_name')
         if not device or not content_type or not name:
             return None
 
         model = content_type.model_class()
         try:
-            termination_object = model.objects.get(
-                device=device,
-                name=name
-            )
+            termination_object = model.objects.get(device=device, name=name)
             if termination_object.cable is not None:
-                raise forms.ValidationError(
-                    "Side A: {} {} is already connected".format(device, termination_object)
-                )
+                raise forms.ValidationError(f"Side {side.upper()}: {device} {termination_object} is already connected")
         except ObjectDoesNotExist:
-            raise forms.ValidationError(
-                "A side termination not found: {} {}".format(device, name)
-            )
+            raise forms.ValidationError(f"{side.upper()} side termination not found: {device} {name}")
 
-        self.instance.termination_a = termination_object
+        setattr(self.instance, f'termination_{side}', termination_object)
         return termination_object
 
-    def clean_side_b_name(self):
-
-        device = self.cleaned_data.get('side_b_device')
-        content_type = self.cleaned_data.get('side_b_type')
-        name = self.cleaned_data.get('side_b_name')
-        if not device or not content_type or not name:
-            return None
-
-        model = content_type.model_class()
-        try:
-            termination_object = model.objects.get(
-                device=device,
-                name=name
-            )
-            if termination_object.cable is not None:
-                raise forms.ValidationError(
-                    "Side B: {} {} is already connected".format(device, termination_object)
-                )
-        except ObjectDoesNotExist:
-            raise forms.ValidationError(
-                "B side termination not found: {} {}".format(device, name)
-            )
+    def clean_side_a_name(self):
+        return self._clean_side('a')
 
-        self.instance.termination_b = termination_object
-        return termination_object
+    def clean_side_b_name(self):
+        return self._clean_side('b')
 
     def clean_length_unit(self):
         # Avoid trying to save as NULL