test_persistence: add VersionIsPoppedFromState test (#673)

1 files changed, 10 insertions, 0 deletions

diff --git a/cloudinit/tests/test_persistence.py b/cloudinit/tests/test_persistence.py
index 7b64ced9..3e5eaa8d 100644
--- a/cloudinit/tests/test_persistence.py
+++ b/cloudinit/tests/test_persistence.py
@@ -99,6 +99,16 @@ class VersionDefaultsToZero(CloudInitPickleMixin, metaclass=_Collector):
         assert 0 == ci_pkl_version
 
 
+class VersionIsPoppedFromState(CloudInitPickleMixin, metaclass=_Collector):
+    """Test _ci_pkl_version is popped from state before being restored."""
+
+    def _unpickle(self, ci_pkl_version: int) -> None:
+        # `self._ci_pkl_version` returns the type's _ci_pkl_version if it isn't
+        # in instance state, so we need to explicitly check self.__dict__.
+        sentinel = mock.sentinel.default
+        assert self.__dict__.get("_ci_pkl_version", sentinel) == sentinel
+
+
 class TestPickleMixin:
     def test_unpickle_called(self):
         """Test that self._unpickle is called on unpickle."""