[tests] Added test ensuring device's related connections

Added a test to ensure only the connections of device are
available on browser api form.
Migrated the validation error from serializer to model
level.

Signed-off-by: DragnEmperor <dragnemperor@gmail.com>

Author: DragnEmperor

openwisp_controller/connection/api/serializers.py

@@ -1,4 +1,3 @@
-from django.utils.translation import gettext_lazy as _
 from rest_framework import serializers
 from swapper import load_model
 
@@ -64,17 +63,6 @@ class Meta:
             'modified',
         ]
 
-    def validate(self, value):
-        super().validate(value)
-        if not DeviceConnection.objects.filter(
-            device=self.context['device_id'],
-            credentials__isnull=False,
-        ).exists():
-            raise serializers.ValidationError(
-                detail={'device': _('Device has no credentials assigned.')}
-            )
-        return value
-
 
 class CredentialSerializer(BaseSerializer):
     params = serializers.JSONField()

openwisp_controller/connection/base/models.py

@@ -459,11 +459,22 @@ def __str__(self):
 
     def clean(self):
         self._verify_command_type_allowed()
+        self._verify_connection()
         try:
             jsonschema.Draft4Validator(self._schema).validate(self.input)
         except SchemaError as e:
             raise ValidationError({'input': e.message})
 
+    def _verify_connection(self):
+        """Raises validation error if device has no connection and credentials."""
+        DeviceConnection = load_model('connection', 'DeviceConnection')
+
+        if not DeviceConnection.objects.filter(
+            device=self.device,
+            credentials__isnull=False,
+        ).exists():
+            raise ValidationError({'device': _('Device has no credentials assigned.')})
+
     def _verify_command_type_allowed(self):
         """Raises validation error if command type is not allowed."""
         # if device is not set, skip to avoid uncaught exception

openwisp_controller/connection/tests/test_api.py

@@ -10,6 +10,7 @@
 from rest_framework.exceptions import ErrorDetail
 from swapper import load_model
 
+from openwisp_controller.connection.api.serializers import CommandSerializer
 from openwisp_controller.tests.utils import TestAdminMixin
 from openwisp_users.tests.test_api import AuthenticationMixin
 
@@ -175,6 +176,28 @@ def test_command_attributes(self, payload):
             self.assertEqual(response.status_code, 201)
             test_command_attributes(self, payload)
 
+    # for ensuring that only related connections are shown
+    def test_available_connections(self):
+        url = self._get_path('device_command_list', self.device_id)
+        response = self.client.get(url)
+        serializer = CommandSerializer(
+            instance=self.device_conn.device,
+            context={'device_id': self.device_id, 'request': response.wsgi_request},
+        )
+        device = self._create_device(
+            name='default.test.device2', mac_address='12:23:34:45:56:67'
+        )
+        self._create_config(device=device)
+        credentials_2 = self._create_credentials(name='Test Credentials 2')
+        device_conn2 = self._create_device_connection(
+            device=device, credentials=credentials_2
+        )
+        connections = serializer.fields['connection']
+        queryset = list(connections.get_queryset().values_list('id', flat=True))
+        queryset = [str(i) for i in queryset]
+        self.assertIn(str(self.device_conn.id), queryset)
+        self.assertNotIn(device_conn2.id, queryset)
+
     def test_command_details_api(self):
         command_obj = self._create_command(device_conn=self.device_conn)
         url = self._get_path('device_command_details', self.device_id, command_obj.id)