feat(wallet): Add fallible Wallet try_get_address(), try_get_internal_address functions when a PersistBackend is used

Author: notmandatory

crates/bdk/src/wallet/mod.rs

@@ -256,6 +256,24 @@ impl Wallet {
                 NewError::Write(_) => unreachable!("mock-write must always succeed"),
             })
     }
+
+    /// Infallibly return a derived address using the external descriptor, see [`AddressIndex`] for
+    /// available address index selection strategies. If none of the keys in the descriptor are derivable
+    /// (i.e. does not end with /*) then the same address will always be returned for any [`AddressIndex`].
+    pub fn get_address(&mut self, address_index: AddressIndex) -> AddressInfo {
+        self.try_get_address(address_index).unwrap()
+    }
+
+    /// Infallibly return a derived address using the internal (change) descriptor.
+    ///
+    /// If the wallet doesn't have an internal descriptor it will use the external descriptor.
+    ///
+    /// see [`AddressIndex`] for available address index selection strategies. If none of the keys
+    /// in the descriptor are derivable (i.e. does not end with /*) then the same address will always
+    /// be returned for any [`AddressIndex`].
+    pub fn get_internal_address(&mut self, address_index: AddressIndex) -> AddressInfo {
+        self.try_get_internal_address(address_index).unwrap()
+    }
 }
 
 /// The error type when constructing a fresh [`Wallet`].
@@ -668,27 +686,37 @@ impl<D> Wallet<D> {
     /// Return a derived address using the external descriptor, see [`AddressIndex`] for
     /// available address index selection strategies. If none of the keys in the descriptor are derivable
     /// (i.e. does not end with /*) then the same address will always be returned for any [`AddressIndex`].
-    pub fn get_address(&mut self, address_index: AddressIndex) -> AddressInfo
+    ///
+    /// A `PersistBackend<ChangeSet>::WriteError` will result if unable to persist the new address
+    /// to the `PersistBackend`.
+    pub fn try_get_address(
+        &mut self,
+        address_index: AddressIndex,
+    ) -> Result<AddressInfo, D::WriteError>
     where
         D: PersistBackend<ChangeSet>,
     {
         self._get_address(KeychainKind::External, address_index)
-            .expect("persistence backend must not fail")
     }
 
     /// Return a derived address using the internal (change) descriptor.
     ///
     /// If the wallet doesn't have an internal descriptor it will use the external descriptor.
     ///
+    /// A `PersistBackend<ChangeSet>::WriteError` will result if unable to persist the new address
+    /// to the `PersistBackend`.
+    ///
     /// see [`AddressIndex`] for available address index selection strategies. If none of the keys
     /// in the descriptor are derivable (i.e. does not end with /*) then the same address will always
     /// be returned for any [`AddressIndex`].
-    pub fn get_internal_address(&mut self, address_index: AddressIndex) -> AddressInfo
+    pub fn try_get_internal_address(
+        &mut self,
+        address_index: AddressIndex,
+    ) -> Result<AddressInfo, D::WriteError>
     where
         D: PersistBackend<ChangeSet>,
     {
         self._get_address(KeychainKind::Internal, address_index)
-            .expect("persistence backend must not fail")
     }
 
     /// Return a derived address using the specified `keychain` (external/internal).

example-crates/wallet_electrum/src/main.rs

@@ -29,7 +29,9 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         Network::Testnet,
     )?;
 
-    let address = wallet.get_address(bdk::wallet::AddressIndex::New);
+    let address = wallet
+        .try_get_address(bdk::wallet::AddressIndex::New)
+        .expect("new_address");
     println!("Generated Address: {}", address);
 
     let balance = wallet.get_balance();

example-crates/wallet_esplora_async/src/main.rs

@@ -27,7 +27,9 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
         Network::Testnet,
     )?;
 
-    let address = wallet.get_address(AddressIndex::New);
+    let address = wallet
+        .try_get_address(AddressIndex::New)
+        .expect("new address");
     println!("Generated Address: {}", address);
 
     let balance = wallet.get_balance();

example-crates/wallet_esplora_blocking/src/main.rs

@@ -26,7 +26,9 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         Network::Testnet,
     )?;
 
-    let address = wallet.get_address(AddressIndex::New);
+    let address = wallet
+        .try_get_address(AddressIndex::New)
+        .expect("new address");
     println!("Generated Address: {}", address);
 
     let balance = wallet.get_balance();