zcash_client_sqlite: Use errors instead of panics for unimplemented or unsupported down migrations.

zcash_client_sqlite/CHANGELOG.md

@@ -31,8 +31,10 @@ and this library adheres to Rust's notion of
   - Added `UnknownZip32Derivation`
   - Added `BadAccountData`
   - Removed `DiversifierIndexOutOfRange`
-- `zcash_client_sqlite::wallet::init::WalletMigrationError` has added variant
-  `AddressGeneration`
+- `zcash_client_sqlite::wallet`:
+  - `init::WalletMigrationError` has added variants:
+    - `WalletMigrationError::AddressGeneration`
+    - `WalletMigrationError::CannotRevert`
 
 ## [0.9.0] - 2024-03-01
 

zcash_client_sqlite/src/wallet/init.rs

@@ -36,6 +36,9 @@ pub enum WalletMigrationError {
 
     /// Wrapper for commitment tree invariant violations
     CommitmentTree(ShardTreeError<commitment_tree::Error>),
+
+    /// Reverting the specified migration is not supported.
+    CannotRevert(Uuid),
 }
 
 impl From<rusqlite::Error> for WalletMigrationError {
@@ -80,6 +83,9 @@ impl fmt::Display for WalletMigrationError {
             WalletMigrationError::AddressGeneration(e) => {
                 write!(f, "Address generation error: {:?}", e)
             }
+            WalletMigrationError::CannotRevert(uuid) => {
+                write!(f, "Reverting migration {} is not supported", uuid)
+            }
         }
     }
 }

zcash_client_sqlite/src/wallet/init/migrations/add_account_birthdays.rs

@@ -69,6 +69,6 @@ impl<P: consensus::Parameters> RusqliteMigration for Migration<P> {
     }
 
     fn down(&self, _transaction: &rusqlite::Transaction) -> Result<(), Self::Error> {
-        panic!("This migration cannot be reverted.");
+        Err(WalletMigrationError::CannotRevert(MIGRATION_ID))
     }
 }

zcash_client_sqlite/src/wallet/init/migrations/add_transaction_views.rs

@@ -266,8 +266,7 @@ impl RusqliteMigration for Migration {
     }
 
     fn down(&self, _transaction: &rusqlite::Transaction) -> Result<(), WalletMigrationError> {
-        // TODO: something better than just panic?
-        panic!("Cannot revert this migration.");
+        Err(WalletMigrationError::CannotRevert(MIGRATION_ID))
     }
 }
 

zcash_client_sqlite/src/wallet/init/migrations/add_utxo_account.rs

@@ -125,8 +125,7 @@ impl<P: consensus::Parameters> RusqliteMigration for Migration<P> {
     }
 
     fn down(&self, _transaction: &rusqlite::Transaction) -> Result<(), WalletMigrationError> {
-        // TODO: something better than just panic?
-        panic!("Cannot revert this migration.");
+        Err(WalletMigrationError::CannotRevert(MIGRATION_ID))
     }
 }
 

zcash_client_sqlite/src/wallet/init/migrations/addresses_table.rs

@@ -174,8 +174,7 @@ impl<P: consensus::Parameters> RusqliteMigration for Migration<P> {
     }
 
     fn down(&self, _transaction: &Transaction) -> Result<(), WalletMigrationError> {
-        // TODO: something better than just panic?
-        panic!("Cannot revert this migration.");
+        Err(WalletMigrationError::CannotRevert(MIGRATION_ID))
     }
 }
 

zcash_client_sqlite/src/wallet/init/migrations/full_account_ids.rs

@@ -427,6 +427,6 @@ impl<P: consensus::Parameters> RusqliteMigration for Migration<P> {
     }
 
     fn down(&self, _transaction: &Transaction) -> Result<(), WalletMigrationError> {
-        panic!("Cannot revert this migration.");
+        Err(WalletMigrationError::CannotRevert(MIGRATION_ID))
     }
 }

zcash_client_sqlite/src/wallet/init/migrations/initial_setup.rs

@@ -104,6 +104,6 @@ impl RusqliteMigration for Migration {
     fn down(&self, _transaction: &rusqlite::Transaction) -> Result<(), WalletMigrationError> {
         // We should never down-migrate the first migration, as that can irreversibly
         // destroy data.
-        panic!("Cannot revert the initial migration.");
+        Err(WalletMigrationError::CannotRevert(MIGRATION_ID))
     }
 }

zcash_client_sqlite/src/wallet/init/migrations/received_notes_nullable_nf.rs

@@ -217,8 +217,7 @@ impl RusqliteMigration for Migration {
     }
 
     fn down(&self, _transaction: &rusqlite::Transaction) -> Result<(), WalletMigrationError> {
-        // TODO: something better than just panic?
-        panic!("Cannot revert this migration.");
+        Err(WalletMigrationError::CannotRevert(MIGRATION_ID))
     }
 }
 

zcash_client_sqlite/src/wallet/init/migrations/receiving_key_scopes.rs

@@ -271,8 +271,7 @@ impl<P: consensus::Parameters> RusqliteMigration for Migration<P> {
     }
 
     fn down(&self, _transaction: &rusqlite::Transaction) -> Result<(), WalletMigrationError> {
-        // TODO: something better than just panic?
-        panic!("Cannot revert this migration.");
+        Err(WalletMigrationError::CannotRevert(MIGRATION_ID))
     }
 }
 

zcash_client_sqlite/src/wallet/init/migrations/sapling_memo_consistency.rs

@@ -212,6 +212,6 @@ impl<P: consensus::Parameters> RusqliteMigration for Migration<P> {
     }
 
     fn down(&self, _: &rusqlite::Transaction) -> Result<(), Self::Error> {
-        panic!("Reversing this migration is not supported.");
+        Err(WalletMigrationError::CannotRevert(MIGRATION_ID))
     }
 }

zcash_client_sqlite/src/wallet/init/migrations/sent_notes_to_internal.rs

@@ -74,7 +74,6 @@ impl RusqliteMigration for Migration {
     }
 
     fn down(&self, _transaction: &rusqlite::Transaction) -> Result<(), WalletMigrationError> {
-        // TODO: something better than just panic?
-        panic!("Cannot revert this migration.");
+        Err(WalletMigrationError::CannotRevert(MIGRATION_ID))
     }
 }

zcash_client_sqlite/src/wallet/init/migrations/shardtree_support.rs

@@ -277,7 +277,6 @@ impl<P: consensus::Parameters> RusqliteMigration for Migration<P> {
     }
 
     fn down(&self, _transaction: &rusqlite::Transaction) -> Result<(), WalletMigrationError> {
-        // TODO: something better than just panic?
-        panic!("Cannot revert this migration.");
+        Err(WalletMigrationError::CannotRevert(MIGRATION_ID))
     }
 }

zcash_client_sqlite/src/wallet/init/migrations/ufvk_support.rs

@@ -260,7 +260,6 @@ impl<P: consensus::Parameters> RusqliteMigration for Migration<P> {
     }
 
     fn down(&self, _transaction: &rusqlite::Transaction) -> Result<(), WalletMigrationError> {
-        // TODO: something better than just panic?
-        panic!("Cannot revert this migration.");
+        Err(WalletMigrationError::CannotRevert(MIGRATION_ID))
     }
 }

zcash_client_sqlite/src/wallet/init/migrations/v_transactions_net.rs

@@ -196,8 +196,7 @@ impl RusqliteMigration for Migration {
     }
 
     fn down(&self, _transaction: &rusqlite::Transaction) -> Result<(), WalletMigrationError> {
-        // TODO: something better than just panic?
-        panic!("Cannot revert this migration.");
+        Err(WalletMigrationError::CannotRevert(MIGRATION_ID))
     }
 }
 

zcash_client_sqlite/src/wallet/init/migrations/v_transactions_note_uniqueness.rs

@@ -154,7 +154,7 @@ impl RusqliteMigration for Migration {
     }
 
     fn down(&self, _transaction: &rusqlite::Transaction) -> Result<(), Self::Error> {
-        panic!("This migration cannot be reverted.");
+        Err(WalletMigrationError::CannotRevert(MIGRATION_ID))
     }
 }
 

zcash_client_sqlite/src/wallet/init/migrations/v_transactions_shielding_balance.rs

@@ -150,6 +150,6 @@ impl RusqliteMigration for Migration {
     }
 
     fn down(&self, _transaction: &rusqlite::Transaction) -> Result<(), Self::Error> {
-        panic!("This migration cannot be reverted.");
+        Err(WalletMigrationError::CannotRevert(MIGRATION_ID))
     }
 }

zcash_client_sqlite/src/wallet/init/migrations/v_transactions_transparent_history.rs

@@ -186,6 +186,6 @@ impl RusqliteMigration for Migration {
     }
 
     fn down(&self, _transaction: &rusqlite::Transaction) -> Result<(), Self::Error> {
-        panic!("This migration cannot be reverted.");
+        Err(WalletMigrationError::CannotRevert(MIGRATION_ID))
     }
 }

zcash_client_sqlite/src/wallet/init/migrations/v_tx_outputs_use_legacy_false.rs

@@ -87,6 +87,6 @@ impl RusqliteMigration for Migration {
     }
 
     fn down(&self, _transaction: &rusqlite::Transaction) -> Result<(), Self::Error> {
-        panic!("This migration cannot be reverted.");
+        Err(WalletMigrationError::CannotRevert(MIGRATION_ID))
     }
 }

zcash_client_sqlite/src/wallet/init/migrations/wallet_summaries.rs

@@ -84,6 +84,6 @@ impl RusqliteMigration for Migration {
     }
 
     fn down(&self, _transaction: &rusqlite::Transaction) -> Result<(), Self::Error> {
-        panic!("This migration cannot be reverted.");
+        Err(WalletMigrationError::CannotRevert(MIGRATION_ID))
     }
 }