created test for when slug exists but not in the nld-data

tests/functional/test_native_land_data_view.py

@@ -20,9 +20,31 @@ def setUp(self):
         )
         self.assertTrue(logged_in, 'Login failed')
 
-    def test_slug_does_not_exist_returns_404(self):
-        kwargs = {}
+    def test_error_raised_when_slug_is_not_defined_in_get_request(self):
+        """
+        When the get request does not contain a slug, it should raise an error.
+        """
         expected_message = 'Slug Variable Is Not Defined In Request'
-        response = self.client.get(reverse('nld-data', kwargs=kwargs))
+        response = self.client.get(
+            reverse('nld-data', {})
+        )
         self.assertEqual(response.status_code, 404)
         self.assertEqual(response.context['exception'], expected_message)
+
+    def test_error_raised_when_slug_is_not_in_nld_data(self):
+        """
+        When the retrieve_native_land_all_slug_data returns an empty dictionary
+        which does not contain the slug, an error should be raised.
+        """
+        slug = 'placeholder_slug'
+        expected_message = f'Unable to Retrieve Specific NLD Slug Data for {slug}'
+        get_variables = {
+            'slug': slug,
+        }
+        with patch('helpers.views.retrieve_native_land_all_slug_data') as mock_function:
+            mock_function.return_value = {}
+            response = self.client.get(
+                reverse('nld-data'),
+                data=get_variables
+            )
+            self.assertEqual(response.context['exception'], expected_message)