#14329 Improve diffs for custom_fields

netbox/core/models/change_logging.py

@@ -199,20 +199,18 @@ class ObjectChange(models.Model):
         # Determine which attributes have changed
         if self.action == ObjectChangeActionChoices.ACTION_CREATE:
             changed_attrs = sorted(postchange_data.keys())
-        elif self.action == ObjectChangeActionChoices.ACTION_DELETE:
-            changed_attrs = sorted(prechange_data.keys())
-        else:
-            diff_added, diff_removed = deep_compare_dict(prechange_data, postchange_data)
             return {
-                'pre': dict(sorted(diff_removed.items())),
-                'post': dict(sorted(diff_added.items())),
+                'pre': {k: prechange_data.get(k) for k in changed_attrs},
+                'post': {k: postchange_data.get(k) for k in changed_attrs},
             }
-
+        if self.action == ObjectChangeActionChoices.ACTION_DELETE:
+            changed_attrs = sorted(prechange_data.keys())
+            return {
+                'pre': {k: prechange_data.get(k) for k in changed_attrs},
+                'post': {k: postchange_data.get(k) for k in changed_attrs},
+            }
+        diff_added, diff_removed = deep_compare_dict(prechange_data, postchange_data)
         return {
-            'pre': {
-                k: prechange_data.get(k) for k in changed_attrs
-            },
-            'post': {
-                k: postchange_data.get(k) for k in changed_attrs
-            },
+            'pre': dict(sorted(diff_removed.items())),
+            'post': dict(sorted(diff_added.items())),
         }

netbox/core/views.py

@@ -274,8 +274,8 @@ class ObjectChangeView(generic.ObjectView):
 
         if prechange_data and instance.postchange_data:
             diff_added, diff_removed = deep_compare_dict(
-                prechange_data or dict(),
-                instance.postchange_data_clean or dict(),
+                prechange_data,
+                instance.postchange_data_clean,
                 exclude=['last_updated'],
             )
         else:

netbox/templates/core/objectchange.html

@@ -124,7 +124,7 @@
                       {% if subdiff.items %}
                         <span>{{ k }}: {</span>
                         {% for sub_k, sub_v in v.items %}
-                          <span{% if sub_k in subdiff %} class="removed"{% endif %} style="padding-left: 2em;">{{ sub_k }}: {{ sub_v|json }}</span>
+                          <span class="ps-4{% if sub_k in subdiff %} removed{% endif %}">{{ sub_k }}: {{ sub_v|json }}</span>
                         {% endfor %}
                         <span>}</span>
                       {% else %}
@@ -154,7 +154,7 @@
                           {% if subdiff.items %}
                             <span>{{ k }}: {</span>
                             {% for sub_k, sub_v in v.items %}
-                              <span{% if sub_k in subdiff %} class="added"{% endif %} style="padding-left: 2em;">{{ sub_k }}: {{ sub_v|json }}</span>
+                              <span class="ps-4{% if sub_k in subdiff %} added{% endif %}">{{ sub_k }}: {{ sub_v|json }}</span>
                             {% endfor %}
                             <span>}</span>
                           {% else %}

netbox/utilities/tests/test_data.py

@@ -3,6 +3,7 @@ from django.test import TestCase
 
 from utilities.data import (
     check_ranges_overlap,
+    deep_compare_dict,
     get_config_value_ci,
     ranges_to_string,
     ranges_to_string_list,
@@ -100,6 +101,64 @@ class RangeFunctionsTestCase(TestCase):
         )
 
 
+class DeepCompareDictTestCase(TestCase):
+
+    def test_no_changes(self):
+        source = {'a': 1, 'b': 'foo', 'c': {'x': 1, 'y': 2}}
+        added, removed = deep_compare_dict(source, source)
+        self.assertEqual(added, {})
+        self.assertEqual(removed, {})
+
+    def test_scalar_change(self):
+        source = {'a': 1, 'b': 'foo'}
+        dest = {'a': 2, 'b': 'foo'}
+        added, removed = deep_compare_dict(source, dest)
+        self.assertEqual(added, {'a': 2})
+        self.assertEqual(removed, {'a': 1})
+
+    def test_key_added(self):
+        source = {'a': 1}
+        dest = {'a': 1, 'b': 'new'}
+        added, removed = deep_compare_dict(source, dest)
+        self.assertEqual(added, {'b': 'new'})
+        self.assertEqual(removed, {'b': None})
+
+    def test_key_removed(self):
+        source = {'a': 1, 'b': 'old'}
+        dest = {'a': 1}
+        added, removed = deep_compare_dict(source, dest)
+        self.assertEqual(added, {'b': None})
+        self.assertEqual(removed, {'b': 'old'})
+
+    def test_nested_dict_partial_change(self):
+        """Only changed sub-keys of a nested dict are included."""
+        source = {'custom_fields': {'cf1': 'old', 'cf2': 'unchanged'}}
+        dest = {'custom_fields': {'cf1': 'new', 'cf2': 'unchanged'}}
+        added, removed = deep_compare_dict(source, dest)
+        self.assertEqual(added, {'custom_fields': {'cf1': 'new'}})
+        self.assertEqual(removed, {'custom_fields': {'cf1': 'old'}})
+
+    def test_nested_dict_no_change(self):
+        source = {'name': 'test', 'custom_fields': {'cf1': 'same'}}
+        added, removed = deep_compare_dict(source, source)
+        self.assertEqual(added, {})
+        self.assertEqual(removed, {})
+
+    def test_mixed_flat_and_nested(self):
+        source = {'name': 'old', 'custom_fields': {'cf1': 'old', 'cf2': 'same'}}
+        dest = {'name': 'new', 'custom_fields': {'cf1': 'new', 'cf2': 'same'}}
+        added, removed = deep_compare_dict(source, dest)
+        self.assertEqual(added, {'name': 'new', 'custom_fields': {'cf1': 'new'}})
+        self.assertEqual(removed, {'name': 'old', 'custom_fields': {'cf1': 'old'}})
+
+    def test_exclude(self):
+        source = {'a': 1, 'last_updated': '2024-01-01'}
+        dest = {'a': 2, 'last_updated': '2024-06-01'}
+        added, removed = deep_compare_dict(source, dest, exclude=['last_updated'])
+        self.assertEqual(added, {'a': 2})
+        self.assertEqual(removed, {'a': 1})
+
+
 class GetConfigValueCITestCase(TestCase):
 
     def test_exact_match(self):