Add reason to Event::PaymentFailed

Author: tnull

bindings/ldk_node.udl

@@ -157,12 +157,21 @@ enum BuildError {
 
 [Enum]
 interface Event {
-	PaymentSuccessful( PaymentHash payment_hash );
-	PaymentFailed( PaymentHash payment_hash );
-	PaymentReceived( PaymentHash payment_hash, u64 amount_msat);
-	ChannelPending ( ChannelId channel_id, UserChannelId user_channel_id, ChannelId former_temporary_channel_id, PublicKey counterparty_node_id, OutPoint funding_txo );
-	ChannelReady ( ChannelId channel_id, UserChannelId user_channel_id, PublicKey? counterparty_node_id );
-	ChannelClosed ( ChannelId channel_id, UserChannelId user_channel_id, PublicKey? counterparty_node_id );
+	PaymentSuccessful(PaymentHash payment_hash);
+	PaymentFailed(PaymentHash payment_hash, PaymentFailureReason? reason);
+	PaymentReceived(PaymentHash payment_hash, u64 amount_msat);
+	ChannelPending(ChannelId channel_id, UserChannelId user_channel_id, ChannelId former_temporary_channel_id, PublicKey counterparty_node_id, OutPoint funding_txo);
+	ChannelReady(ChannelId channel_id, UserChannelId user_channel_id, PublicKey? counterparty_node_id);
+	ChannelClosed(ChannelId channel_id, UserChannelId user_channel_id, PublicKey? counterparty_node_id);
+};
+
+enum PaymentFailureReason {
+	"RecipientRejected",
+	"UserAbandoned",
+	"RetriesExhausted",
+	"PaymentExpired",
+	"RouteNotFound",
+	"UnexpectedError",
 };
 
 enum PaymentDirection {

src/event.rs

@@ -14,8 +14,8 @@ use crate::io::{
 use crate::logger::{log_error, log_info, Logger};
 
 use lightning::chain::chaininterface::ConfirmationTarget;
-use lightning::events::Event as LdkEvent;
 use lightning::events::PaymentPurpose;
+use lightning::events::{Event as LdkEvent, PaymentFailureReason};
 use lightning::impl_writeable_tlv_based_enum;
 use lightning::ln::{ChannelId, PaymentHash};
 use lightning::routing::gossip::NodeId;
@@ -52,6 +52,10 @@ pub enum Event {
 	PaymentFailed {
 		/// The hash of the payment.
 		payment_hash: PaymentHash,
+		/// The reason why the payment failed.
+		///
+		/// This will be `None` for events serialized by LDK Node v0.2.1 and prior.
+		reason: Option<PaymentFailureReason>,
 	},
 	/// A payment has been received.
 	PaymentReceived {
@@ -103,6 +107,7 @@ impl_writeable_tlv_based_enum!(Event,
 	},
 	(1, PaymentFailed) => {
 		(0, payment_hash, required),
+		(1, reason, option),
 	},
 	(2, PaymentReceived) => {
 		(0, payment_hash, required),
@@ -609,11 +614,12 @@ where
 						panic!("Failed to push to event queue");
 					});
 			}
-			LdkEvent::PaymentFailed { payment_hash, .. } => {
+			LdkEvent::PaymentFailed { payment_hash, reason, .. } => {
 				log_info!(
 					self.logger,
-					"Failed to send payment to payment hash {:?}.",
-					hex_utils::to_string(&payment_hash.0)
+					"Failed to send payment to payment hash {:?} due to {:?}.",
+					hex_utils::to_string(&payment_hash.0),
+					reason
 				);
 
 				let update = PaymentDetailsUpdate {
@@ -624,12 +630,12 @@ where
 					log_error!(self.logger, "Failed to access payment store: {}", e);
 					panic!("Failed to access payment store");
 				});
-				self.event_queue.add_event(Event::PaymentFailed { payment_hash }).unwrap_or_else(
-					|e| {
+				self.event_queue
+					.add_event(Event::PaymentFailed { payment_hash, reason })
+					.unwrap_or_else(|e| {
 						log_error!(self.logger, "Failed to push to event queue: {}", e);
 						panic!("Failed to push to event queue");
-					},
-				);
+					});
 			}
 
 			LdkEvent::PaymentPathSuccessful { .. } => {}

src/lib.rs

@@ -108,7 +108,10 @@ pub use types::ChannelConfig;
 pub use io::utils::generate_entropy_mnemonic;
 
 #[cfg(feature = "uniffi")]
-use {bip39::Mnemonic, bitcoin::OutPoint, lightning::ln::PaymentSecret, uniffi_types::*};
+use {
+	bip39::Mnemonic, bitcoin::OutPoint, lightning::events::PaymentFailureReason,
+	lightning::ln::ChannelId, lightning::ln::PaymentSecret, uniffi_types::*,
+};
 
 #[cfg(feature = "uniffi")]
 pub use builder::ArcedNodeBuilder as Builder;
@@ -135,8 +138,6 @@ use lightning::ln::channelmanager::{self, PaymentId, RecipientOnionFields, Retry
 use lightning::ln::msgs::SocketAddress;
 use lightning::ln::{PaymentHash, PaymentPreimage};
 
-#[cfg(feature = "uniffi")]
-use lightning::ln::ChannelId;
 use lightning::sign::EntropySource;
 
 use lightning::util::persist::KVStore;