Fixed persistent state with outdated data + updated Bincode docs

CHANGELOG.md

@@ -28,6 +28,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Now Vec<MessageId> in requests serializes into [number] instead of [ {message_id: number} ], `forward_messages`, `copy_messages` and `delete_messages` now work properly
 - Now `InlineQueryResultsButton` serializes properly ([issue 1181](https://github.com/teloxide/teloxide/issues/1181))
 - Now `ThreadId` is able to serialize in multipart requests ([PR 1179](https://github.com/teloxide/teloxide/pull/1179))
+- Now persistent state storage won't break if the data is outdated ([issue 1156](https://github.com/teloxide/teloxide/issues/1156))
 
 ## 0.13.0 - 2024-08-16
 

crates/teloxide/src/dispatching/dialogue.rs

@@ -232,8 +232,9 @@ where
         match dialogue.get_or_default().await {
             Ok(dialogue) => Some(dialogue),
             Err(err) => {
-                log::error!("dialogue.get_or_default() failed: {:?}", err);
-                None
+                log::error!("dialogue.get_or_default() failed: {:?}, falling back to default", err);
+                dialogue.update(D::default()).await.ok()?;
+                dialogue.get_or_default().await.ok()
             }
         }
     })

crates/teloxide/src/dispatching/dialogue/storage/serializer.rs

@@ -52,7 +52,13 @@ where
 
 /// The [Bincode] serializer for memory storages.
 ///
+/// Can't serialize if the length is unknown, [see this issue](https://github.com/bincode-org/bincode/issues/167).
+/// Use [`Cbor`] or [`Json`] if you are storing structs like [`Message`].
+///
 /// [Bincode]: https://github.com/servo/bincode
+/// [`Cbor`]: crate::dispatching::dialogue::serializer::Cbor
+/// [`Json`]: crate::dispatching::dialogue::serializer::Json
+/// [`Message`]: crate::types::Message
 #[cfg(feature = "bincode-serializer")]
 pub struct Bincode;