UPDATE

device_hub/tests.py

@@ -5,6 +5,7 @@ from rest_framework.test import APIRequestFactory, force_authenticate
 from farm_hub.models import FarmHub, FarmType
 
 from .models import DeviceCatalog, SensorExternalRequestLog
+from .services import DeviceDataUnavailableError, build_device_anomaly_detection_card
 from .views import DeviceCommandView, DeviceDetailView, DeviceLatestPayloadView, DeviceSummaryView
 
 
@@ -91,6 +92,27 @@ class DeviceHubGenericViewsTests(TestCase):
         self.assertIn("values_list", response.data["data"]["supportedWidgets"])
         self.assertIn("sensorValuesList", response.data["data"])
 
+    def test_device_summary_view_returns_validation_error_when_history_missing(self):
+        SensorExternalRequestLog.objects.all().delete()
+        request = self.factory.get(
+            f"/api/device-hub/devices/{self.device.physical_device_uuid}/summary/",
+            {"device_code": self.catalog.code},
+        )
+        force_authenticate(request, user=self.user)
+
+        response = DeviceSummaryView.as_view()(request, physical_device_uuid=self.device.physical_device_uuid)
+
+        self.assertEqual(response.status_code, 400)
+        self.assertIn("no device history found", response.data["device_code"][0].lower())
+
+    def test_build_device_anomaly_detection_card_returns_explicit_empty_success(self):
+        payload = build_device_anomaly_detection_card(self.device)
+
+        self.assertEqual(payload["status"], "success")
+        self.assertEqual(payload["source"], "db")
+        self.assertEqual(payload["anomalies"], [])
+        self.assertTrue(payload["warnings"])
+
     def test_input_only_device_command_view_rejects_input_only_device_code(self):
         input_catalog = DeviceCatalog.objects.create(
             code="valve_v1",