Handle errors due to invalid responses in deserialize(), so it applies to other methods besides just get_responses()

1 files changed, 16 insertions, 8 deletions

diff --git a/requests_cache/backends/base.py b/requests_cache/backends/base.py
index bc57ca1..825cd55 100644
--- a/requests_cache/backends/base.py
+++ b/requests_cache/backends/base.py
@@ -70,11 +70,7 @@ class BaseCache:
                 response = self.responses[self.redirects[key]]
             response.cache_key = key
             return response
-        except KeyError:
-            return default
-        except DESERIALIZE_ERRORS as e:
-            logger.error(f'Unable to deserialize response {key}: {str(e)}')
-            logger.debug(e, exc_info=True)
+        except (AttributeError, KeyError):
             return default
 
     def save_response(self, response: Response, cache_key: str = None, expires: datetime = None):
@@ -394,16 +390,28 @@ class BaseStorage(MutableMapping[KT, VT], ABC):
         """Close any open backend connections"""
 
     def serialize(self, value: VT):
-        """Serialize value, if a serializer is available"""
+        """Serialize a value, if a serializer is available"""
         if TYPE_CHECKING:
             assert hasattr(self.serializer, 'dumps')
         return self.serializer.dumps(value) if self.serializer else value
 
     def deserialize(self, value: VT):
-        """Deserialize value, if a serializer is available"""
+        """Deserialize a value, if a serializer is available.
+
+        If deserialization fails (usually due to a value saved in an older requests-cache version),
+        ``None`` will be returned.
+        """
+        if not self.serializer:
+            return value
         if TYPE_CHECKING:
             assert hasattr(self.serializer, 'loads')
-        return self.serializer.loads(value) if self.serializer else value
+
+        try:
+            return self.serializer.loads(value)
+        except DESERIALIZE_ERRORS as e:
+            logger.error(f'Unable to deserialize response: {str(e)}')
+            logger.debug(e, exc_info=True)
+            return None
 
     def __str__(self):
         return str(list(self.keys()))