add serializers tests in API

cadasta/accounts/tests/test_serializers.py

@@ -310,6 +310,38 @@ def test_update_with_restricted_username(self):
         assert serializer2.errors['username'] == [
             _("Username cannot be “add” or “new”.")]
 
+    def test_update_with_invalid_language(self):
+        serializer = serializers.UserSerializer(data=BASIC_TEST_DATA)
+        assert serializer.is_valid() is True
+        user = serializer.save()
+        data = {
+            'username': 'imagine71',
+            'email': '[email protected]',
+            'language': 'invalid',
+        }
+        request = APIRequestFactory().patch('/user/imagine71', data)
+        force_authenticate(request, user=user)
+        serializer2 = serializers.UserSerializer(
+            user, data=data, context={'request': Request(request)}
+        )
+        assert serializer2.is_valid() is False
+
+    def test_update_with_invalid_measurement_system(self):
+        serializer = serializers.UserSerializer(data=BASIC_TEST_DATA)
+        assert serializer.is_valid() is True
+        user = serializer.save()
+        data = {
+            'username': 'imagine71',
+            'email': '[email protected]',
+            'measurement': 'invalid',
+        }
+        request = APIRequestFactory().patch('/user/imagine71', data)
+        force_authenticate(request, user=user)
+        serializer2 = serializers.UserSerializer(
+            user, data=data, context={'request': Request(request)}
+        )
+        assert serializer2.is_valid() is False
+
     def test_sanitize(self):
         user = UserFactory.create(username='imagine71')
         data = {