Add derivation_index to GetAddressResult

The derivation index is required for
for client to derive and verify the address
on hardware wallets.

Co-Authored-By: Antoine Poinsot <darosior@protonmail.com>

src/commands/mod.rs

@@ -306,7 +306,7 @@ impl DaemonControl {
             .receive_descriptor()
             .derive(index, &self.secp)
             .address(self.config.bitcoin_config.network);
-        GetAddressResult::new(address)
+        GetAddressResult::new(address, index)
     }
 
     /// list addresses
@@ -945,7 +945,17 @@ pub struct GetInfoResult {
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct GetAddressResult {
     #[serde(deserialize_with = "deser_addr_assume_checked")]
-    address: bitcoin::Address,
+    pub address: bitcoin::Address,
+    pub derivation_index: bip32::ChildNumber,
+}
+
+impl GetAddressResult {
+    pub fn new(address: bitcoin::Address, derivation_index: bip32::ChildNumber) -> Self {
+        Self {
+            address,
+            derivation_index,
+        }
+    }
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -953,16 +963,6 @@ pub struct GetLabelsResult {
     pub labels: HashMap<String, String>,
 }
 
-impl GetAddressResult {
-    pub fn new(address: bitcoin::Address) -> Self {
-        Self { address }
-    }
-
-    pub fn address(&self) -> &bitcoin::Address {
-        &self.address
-    }
-}
-
 #[derive(Debug, Clone, Serialize, PartialEq, Eq)]
 pub struct AddressInfo {
     index: u32,

tests/test_rpc.py

@@ -35,6 +35,8 @@ def test_getaddress(lianad):
     assert "address" in res
     # We'll get a new one at every call
     assert res["address"] != lianad.rpc.getnewaddress()["address"]
+    # new address has derivation_index higher than the previous one
+    assert lianad.rpc.getnewaddress()["derivation_index"] == res["derivation_index"] + 2
 
 
 def test_listaddresses(lianad):