f - return Result from MessageRouter::find_route

Author: jkczyz

fuzz/src/onion_message.rs

@@ -58,7 +58,9 @@ pub extern "C" fn onion_message_run(data: *const u8, datalen: usize) {
 struct TestMessageRouter {}
 
 impl MessageRouter for TestMessageRouter {
-	fn find_route(&self, _sender: &PublicKey, _destination: &Destination) -> Option<Vec<PublicKey>> {
+	fn find_route(
+		&self, _sender: &PublicKey, _destination: &Destination
+	) -> Result<Vec<PublicKey>, ()> {
 		unreachable!()
 	}
 }

lightning/src/onion_message/functional_tests.rs

@@ -48,7 +48,9 @@ impl MessengerNode {
 struct TestMessageRouter {}
 
 impl MessageRouter for TestMessageRouter {
-	fn find_route(&self, _sender: &PublicKey, _destination: &Destination) -> Option<Vec<PublicKey>> {
+	fn find_route(
+		&self, _sender: &PublicKey, _destination: &Destination
+	) -> Result<Vec<PublicKey>, ()> {
 		todo!()
 	}
 }

lightning/src/onion_message/messenger.rs

@@ -58,7 +58,7 @@ use crate::prelude::*;
 /// # }
 /// # struct FakeMessageRouter {}
 /// # impl MessageRouter for FakeMessageRouter {
-/// #     fn find_route(&self, sender: &PublicKey, destination: &Destination) -> Option<Vec<PublicKey>> {
+/// #     fn find_route(&self, sender: &PublicKey, destination: &Destination) -> Result<Vec<PublicKey>, ()> {
 /// #         unimplemented!()
 /// #     }
 /// # }
@@ -145,7 +145,9 @@ pub trait MessageRouter {
 	/// This should include only intermediate nodes between `sender` and `destination`.
 	///
 	/// [`OnionMessage`]: msgs::OnionMessage
-	fn find_route(&self, sender: &PublicKey, destination: &Destination) -> Option<Vec<PublicKey>>;
+	fn find_route(
+		&self, sender: &PublicKey, destination: &Destination
+	) -> Result<Vec<PublicKey>, ()>;
 }
 
 /// The destination of an onion message.