[fix] Skip connection check when firmware image unchanged

Author: Eeshu-Yadav

openwisp_firmware_upgrader/base/models.py

@@ -409,7 +409,7 @@ def clean(self):
                     )
                 }
             )
-        if self.device.deviceconnection_set.count() < 1:
+        if self.image_has_changed and self.device.deviceconnection_set.count() < 1:
             raise ValidationError(
                 _(
                     "This device does not have a related connection object defined "

openwisp_firmware_upgrader/tests/test_api.py

@@ -1309,7 +1309,7 @@ def test_device_firmware_detail_400(self):
 
         with self.subTest("Test device and image model validation"):
             url = reverse("upgrader:api_devicefirmware_detail", args=[device1.pk])
-            with self.assertNumQueries(18):
+            with self.assertNumQueries(17):
                 # Try to make a request when the
                 # device model does not match the image model
                 data = {"image": image1a.pk}
@@ -1490,7 +1490,7 @@ def test_device_firmware_detail_update(self):
         self.assertEqual(DeviceFirmware.objects.count(), 2)
         self.assertEqual(UpgradeOperation.objects.count(), 0)
 
-        with self.assertNumQueries(27):
+        with self.assertNumQueries(26):
             data = {"image": image2a.pk}
             r = self.client.put(
                 f"{url}?format=api", data, content_type="application/json"
@@ -1529,7 +1529,7 @@ def test_device_firmware_detail_partial_update(self):
         self.assertEqual(DeviceFirmware.objects.count(), 2)
         self.assertEqual(UpgradeOperation.objects.count(), 0)
 
-        with self.assertNumQueries(27):
+        with self.assertNumQueries(26):
             data = {"image": image2a.pk}
             r = self.client.patch(
                 f"{url}?format=api", data, content_type="application/json"

openwisp_firmware_upgrader/tests/test_models.py

@@ -177,14 +177,14 @@ def test_device_fw_no_connection(self):
         else:
             self.fail("ValidationError not raised")
 
-    def test_device_fw_credentials_removed_after_assignment(self):
+    def test_device_fw_save_after_credentials_removed(self):
         """Regression test for #250."""
         device_fw = self._create_device_firmware()
-        device_fw.upgrade_options = {"n": True}
         device_fw.device.deviceconnection_set.all().delete()
-        with self.assertRaises(ValidationError) as ctx:
-            device_fw.full_clean()
-        self.assertIn("connection", str(ctx.exception).lower())
+        device_fw.full_clean()
+        uo_count = UpgradeOperation.objects.count()
+        device_fw.save(upgrade=False)
+        self.assertEqual(UpgradeOperation.objects.count(), uo_count)
 
     def test_invalid_board(self):
         image = FIRMWARE_IMAGE_MAP[self.TPLINK_4300_IMAGE]