fix: preserve cable paths across export and import

tests/test_cable_import.py

@@ -0,0 +1,80 @@
+from types import SimpleNamespace
+from unittest.mock import MagicMock
+
+from netbox_export.services import importer
+from netbox_export.services.importer import (
+    _rebuild_imported_cable_paths,
+    _release_port_mapping_conflicts,
+)
+
+
+class FakeQuerySet(list):
+    def exclude(self, **kwargs):
+        return FakeQuerySet(item for item in self if item.pk != kwargs["pk"])
+
+    def order_by(self, *args):
+        return self
+
+
+class FakeManager:
+    def __init__(self, objects):
+        self.objects = FakeQuerySet(objects)
+        self.filters = []
+
+    def select_for_update(self):
+        return self
+
+    def filter(self, *args, **kwargs):
+        self.filters.append((args, kwargs))
+        return FakeQuerySet(self.objects)
+
+
+def test_port_mapping_conflicts_are_replaced_before_save():
+    deleted = []
+    conflict = SimpleNamespace(pk=12, delete=lambda: deleted.append(12))
+
+    class PortMapping:
+        _meta = SimpleNamespace(label_lower="dcim.portmapping")
+        _default_manager = FakeManager([conflict])
+
+    mapping = PortMapping()
+    mapping.pk = 11
+    mapping.front_port_id = 21
+    mapping.front_port_position = 1
+    mapping.rear_port_id = 31
+    mapping.rear_port_position = 1
+    resolver = SimpleNamespace(warn=MagicMock())
+
+    _release_port_mapping_conflicts(mapping, resolver, "dcim.portmapping:99")
+
+    assert deleted == [12]
+    resolver.warn.assert_called_once()
+    assert "Front-/Rear-Port-Verkabelung" in resolver.warn.call_args.args[1]
+
+
+def test_imported_cable_terminations_trigger_netbox_path_rebuild(monkeypatch):
+    cables = [SimpleNamespace(pk=7), SimpleNamespace(pk=9)]
+
+    class Cable:
+        _default_manager = FakeManager(cables)
+
+    trace_paths = SimpleNamespace(send=MagicMock())
+    monkeypatch.setattr(importer, "_model_for", lambda label: Cable)
+    monkeypatch.setattr(importer, "_trace_paths_signal", lambda: trace_paths)
+    records = {
+        "dcim.cabletermination:1": {"model": "dcim.cabletermination"},
+        "dcim.cabletermination:2": {"model": "dcim.cabletermination"},
+        "dcim.device:3": {"model": "dcim.device"},
+    }
+    resolved = {
+        "dcim.cabletermination:1": SimpleNamespace(cable_id=7),
+        "dcim.cabletermination:2": SimpleNamespace(cable_id=9),
+        "dcim.device:3": object(),
+    }
+
+    _rebuild_imported_cable_paths(records, resolved)
+
+    assert all(cable._terminations_modified is True for cable in cables)
+    assert trace_paths.send.call_count == 2
+    trace_paths.send.assert_any_call(Cable, instance=cables[0], created=False)
+    trace_paths.send.assert_any_call(Cable, instance=cables[1], created=False)

tests/test_graph.py

@@ -43,10 +43,29 @@ class PrivateGraphModel(models.Model):
         app_label = "graph_tests"
 
 
+class PortMapping(models.Model):
+    _netbox_private = True
+
+    class Meta:
+        app_label = "dcim"
+
+
+class CablePath(models.Model):
+    _netbox_private = True
+
+    class Meta:
+        app_label = "dcim"
+
+
 def test_private_plugin_models_are_not_exportable():
     assert graph_module.is_exportable_model(PrivateGraphModel) is False
 
 
+def test_private_port_mappings_are_exported_but_cable_paths_are_not():
+    assert graph_module.is_exportable_model(PortMapping) is True
+    assert graph_module.is_exportable_model(CablePath) is False
+
+
 def test_batched_graph_collects_members_and_dependencies(monkeypatch):
     graph_models = (GraphParent, GraphReference, GraphChild, GraphDetail)
     with connection.schema_editor() as schema_editor: