Test for deserialization between versions (#1389)

xmtp_mls/src/preferences.rs

@@ -5,9 +5,10 @@ use xmtp_proto::xmtp::mls::message_contents::UserPreferenceUpdate as UserPrefere
 use crate::storage::consent_record::StoredConsentRecord;
 
 #[derive(Serialize, Deserialize, Clone)]
+#[repr(i32)]
 pub enum UserPreferenceUpdate {
-    ConsentUpdate(StoredConsentRecord),
-    HmacKeyUpdate { key: Vec<u8> },
+    ConsentUpdate(StoredConsentRecord) = 1,
+    HmacKeyUpdate { key: Vec<u8> } = 2,
 }
 
 impl TryFrom<UserPreferenceUpdateProto> for UserPreferenceUpdate {
@@ -28,3 +29,34 @@ impl TryInto<UserPreferenceUpdateProto> for UserPreferenceUpdate {
         Ok(UserPreferenceUpdateProto { content })
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::storage::consent_record::{ConsentState, ConsentType};
+
+    use super::*;
+
+    #[derive(Serialize, Deserialize, Clone)]
+    #[repr(i32)]
+    enum OldUserPreferenceUpdate {
+        ConsentUpdate(StoredConsentRecord) = 1,
+    }
+
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
+    #[cfg_attr(not(target_arch = "wasm32"), tokio::test)]
+    async fn test_can_deserialize_between_versions() {
+        let consent_record = StoredConsentRecord {
+            entity: "hello there".to_string(),
+            entity_type: ConsentType::Address,
+            state: ConsentState::Allowed,
+        };
+        let update = UserPreferenceUpdate::ConsentUpdate(consent_record);
+
+        let bytes = bincode::serialize(&update).unwrap();
+
+        let old_update: OldUserPreferenceUpdate = bincode::deserialize(&bytes).unwrap();
+
+        let OldUserPreferenceUpdate::ConsentUpdate(update) = old_update;
+        assert_eq!(update.state, ConsentState::Allowed);
+    }
+}