refactor: replace panic statements with appropriate build error

Author: enigbe

bindings/ldk_node.udl

@@ -78,6 +78,7 @@ interface Builder {
 	void set_chain_source_esplora(string server_url, EsploraSyncConfig? config);
 	void set_chain_source_electrum(string server_url, ElectrumSyncConfig? config);
 	void set_chain_source_bitcoind_rpc(string rpc_host, u16 rpc_port, string rpc_user, string rpc_password);
+	[Throws=BuildError]
 	void set_chain_source_bitcoind_rest(string rest_host, u16 rest_port);
 	void set_gossip_source_p2p();
 	void set_gossip_source_rgs(string rgs_server_url);
@@ -338,6 +339,8 @@ enum BuildError {
 	"WalletSetupFailed",
 	"LoggerSetupFailed",
 	"NetworkMismatch",
+	"MissingBitcoindRpcConfig",
+	"InvalidChainSourceConfig",
 };
 
 [Trait]

src/builder.rs

@@ -185,6 +185,17 @@ pub enum BuildError {
 	LoggerSetupFailed,
 	/// The given network does not match the node's previously configured network.
 	NetworkMismatch,
+	/// The RPC configuration for Bitcoin Core is incomplete or missing.
+	///
+	/// This error occurs in two scenarios:
+	/// 1. When the RPC configuration fields (host, port, user, password) are empty or invalid.
+	/// 2. When attempting to configure REST synchronization before setting up RPC configuration.
+	MissingBitcoindRpcConfig,
+	/// Invalid chain source configuration.
+	///
+	/// This error occurs when attempting to set Bitcoin Core REST configuration on a non-Bitcoind
+	/// chain source (such as when the chain source is already configured for Esplora/Electrum).
+	InvalidChainSourceConfig,
 }
 
 impl fmt::Display for BuildError {
@@ -212,6 +223,12 @@ impl fmt::Display for BuildError {
 			Self::NetworkMismatch => {
 				write!(f, "Given network does not match the node's previously configured network.")
 			},
+			Self::MissingBitcoindRpcConfig => {
+				write!(f, "Failed to configure RPC client for ChainSource::Bitcoind.")
+			},
+			Self::InvalidChainSourceConfig => {
+				write!(f, "Given REST client configuration is invalid for the ChainSource variant.")
+			},
 		}
 	}
 }
@@ -343,7 +360,7 @@ impl NodeBuilder {
 	/// * `rest_host`, `rest_port` - Required parameters for the Bitcoin Core REST connection.
 	pub fn set_chain_source_bitcoind_rest(
 		&mut self, rest_host: String, rest_port: u16,
-	) -> &mut Self {
+	) -> Result<&mut Self, BuildError> {
 		let rest_client_config = BitcoindRestSyncClientConfig { rest_host, rest_port };
 
 		match &mut self.chain_data_source_config {
@@ -359,20 +376,22 @@ impl NodeBuilder {
 					|| rpc_user.is_empty()
 					|| rpc_password.is_empty()
 				{
-					panic!("RPC configuration is incomplete. Must fully configure via RPC first.");
+					return Err(BuildError::MissingBitcoindRpcConfig);
 				}
 
 				*sync_client_config = Some(rest_client_config);
 			},
-			Some(cs) => {
-				panic!("This option is only valid for ChainSource::Bitcoind. Current chain source config: {cs:?}")
+			Some(_) => {
+				// This option is only valid for ChainSource::Bitcoind.
+				return Err(BuildError::InvalidChainSourceConfig);
 			},
 			None => {
-				panic!("Must configure via RPC first.")
+				// Must configure via RPC first.
+				return Err(BuildError::MissingBitcoindRpcConfig);
 			},
 		}
 
-		self
+		Ok(self)
 	}
 	/// Configures the [`Node`] instance to source its gossip data from the Lightning peer-to-peer
 	/// network.
@@ -810,8 +829,10 @@ impl ArcedNodeBuilder {
 	///
 	/// ## Parameters:
 	/// * `rest_host`, `rest_port` - Required parameters for the Bitcoin Core REST connection.
-	pub fn set_chain_source_bitcoind_rest(&self, rest_host: String, rest_port: u16) {
-		self.inner.write().unwrap().set_chain_source_bitcoind_rest(rest_host, rest_port);
+	pub fn set_chain_source_bitcoind_rest(
+		&self, rest_host: String, rest_port: u16,
+	) -> Result<(), BuildError> {
+		self.inner.write().unwrap().set_chain_source_bitcoind_rest(rest_host, rest_port).map(|_| ())
 	}
 
 	/// Configures the [`Node`] instance to source its gossip data from the Lightning peer-to-peer

tests/common/mod.rs

@@ -335,9 +335,8 @@ pub(crate) fn setup_node(
 			let rpc_password = values.password;
 			let rest_host = bitcoind.params.rpc_socket.ip().to_string();
 			let rest_port = bitcoind.params.rpc_socket.port();
-			builder
-				.set_chain_source_bitcoind_rpc(rpc_host, rpc_port, rpc_user, rpc_password)
-				.set_chain_source_bitcoind_rest(rest_host, rest_port);
+			builder.set_chain_source_bitcoind_rpc(rpc_host, rpc_port, rpc_user, rpc_password);
+			builder.set_chain_source_bitcoind_rest(rest_host, rest_port).unwrap();
 		},
 	}