Add is_mine method on Wallet type

Closes #354

bdk-ffi/src/bdk.udl

@@ -221,28 +221,31 @@ interface Wallet {
   [Throws=BdkError]
   constructor(Descriptor descriptor, Descriptor? change_descriptor, Network network, DatabaseConfig database_config);
 
+  Network network();
+
   [Throws=BdkError]
   AddressInfo get_address(AddressIndex address_index);
 
   [Throws=BdkError]
   AddressInfo get_internal_address(AddressIndex address_index);
 
+  [Throws=BdkError]
+  boolean is_mine(Script script);
+
+  [Throws=BdkError]
+  sequence<LocalUtxo> list_unspent();
+
+  [Throws=BdkError]
+  sequence<TransactionDetails> list_transactions(boolean include_raw);
+
   [Throws=BdkError]
   Balance get_balance();
 
   [Throws=BdkError]
   boolean sign([ByRef] PartiallySignedTransaction psbt, SignOptions? sign_options);
 
-  [Throws=BdkError]
-  sequence<TransactionDetails> list_transactions(boolean include_raw);
-
-  Network network();
-
   [Throws=BdkError]
   void sync([ByRef] Blockchain blockchain, Progress? progress);
-
-  [Throws=BdkError]
-  sequence<LocalUtxo> list_unspent();
 };
 
 interface FeeRate {

bdk-ffi/src/wallet.rs

@@ -65,6 +65,11 @@ impl Wallet {
         self.get_wallet().network()
     }
 
+    /// Return whether or not a script is part of this wallet (either internal or external).
+    pub(crate) fn is_mine(&self, script: Arc<Script>) -> Result<bool, BdkError> {
+        Ok(self.get_wallet().is_mine(&script.script)?)
+    }
+
     /// Sync the internal database with the blockchain.
     pub(crate) fn sync(
         &self,
@@ -560,9 +565,12 @@ impl BumpFeeTxBuilder {
 mod test {
     use crate::database::DatabaseConfig;
     use crate::descriptor::Descriptor;
+    use crate::keys::{DescriptorSecretKey, Mnemonic};
     use crate::wallet::{AddressIndex, TxBuilder, Wallet};
+    use crate::Script;
     use bdk::bitcoin::{Address, Network};
     use bdk::wallet::get_funded_wallet;
+    use bdk::KeychainKind;
     use std::str::FromStr;
     use std::sync::{Arc, Mutex};
 
@@ -802,4 +810,47 @@ mod test {
             "bcrt1qaux734vuhykww9632v8cmdnk7z2mw5lsf74v6k"
         );
     }
+
+    #[test]
+    fn test_is_mine() {
+        // is_mine should return true for addresses generated by the wallet
+        let mnemonic: Mnemonic = Mnemonic::from_string("chaos fabric time speed sponsor all flat solution wisdom trophy crack object robot pave observe combine where aware bench orient secret primary cable detect".to_string()).unwrap();
+        let secret_key: DescriptorSecretKey =
+            DescriptorSecretKey::new(Network::Testnet, Arc::new(mnemonic), None);
+        let descriptor: Descriptor = Descriptor::new_bip84(
+            Arc::new(secret_key),
+            KeychainKind::External,
+            Network::Testnet,
+        );
+        let wallet: Wallet = Wallet::new(
+            Arc::new(descriptor),
+            None,
+            Network::Testnet,
+            DatabaseConfig::Memory,
+        )
+        .unwrap();
+
+        let address = wallet.get_address(AddressIndex::New).unwrap();
+        let script: Arc<Script> = address.address.script_pubkey();
+
+        let is_mine_1: bool = wallet.is_mine(script).unwrap();
+        assert_eq!(is_mine_1, true);
+
+        // is_mine returns false when provided a script that is not in the wallet
+        let other_wpkh = "wpkh(tprv8hwWMmPE4BVNxGdVt3HhEERZhondQvodUY7Ajyseyhudr4WabJqWKWLr4Wi2r26CDaNCQhhxEftEaNzz7dPGhWuKFU4VULesmhEfZYyBXdE/0/*)";
+        let other_descriptor = Descriptor::new(other_wpkh.to_string(), Network::Testnet).unwrap();
+
+        let other_wallet = Wallet::new(
+            Arc::new(other_descriptor),
+            None,
+            Network::Testnet,
+            DatabaseConfig::Memory,
+        )
+        .unwrap();
+
+        let other_address = other_wallet.get_address(AddressIndex::New).unwrap();
+        let other_script: Arc<Script> = other_address.address.script_pubkey();
+        let is_mine_2: bool = wallet.is_mine(other_script).unwrap();
+        assert_eq!(is_mine_2, false);
+    }
 }