test: increase test coverage

tests/unit/test_upgrade.py

@@ -1,7 +1,7 @@
 # Copyright 2024 Canonical Ltd.
 # See LICENSE file for licensing details.
 import unittest
-from unittest.mock import Mock, PropertyMock, patch
+from unittest.mock import MagicMock, Mock, PropertyMock, patch
 
 import httpx
 import pytest
@@ -123,6 +123,23 @@ def test__get_unit_healthy_status(
         assert isinstance(status, ActiveStatus)
         assert ("(outdated)" in status.message) == outdated_in_status
 
+    @patch("charm.k8s_upgrade.lightkube.Client.list")
+    def test_unit_workload_container_version(self, mock_list):
+        mock_pod = MagicMock()
+        mock_pod.metadata.name = "mongodb-k8s-0"
+        mock_pod.metadata.labels = {"controller-revision-hash": "deadbeef"}
+        mock_list.return_value = (mock_pod,)
+        versions = self.harness.charm.upgrade._upgrade._unit_workload_container_versions
+        assert versions == {"mongodb-k8s/0": "deadbeef"}
+
+    @patch("charm.k8s_upgrade.lightkube.Client.get")
+    def test_app_workload_container_revision(self, mock_get):
+        mock_stateful_set = MagicMock()
+        mock_stateful_set.status.updateRevision = "deadbeef"
+        mock_get.return_value = mock_stateful_set
+        version = self.harness.charm.upgrade._upgrade._app_workload_container_version
+        assert version == "deadbeef"
+
     @parameterized.expand(
         [
             [None, True, ActiveStatus(), "restarting", False],