Split SendReceive into seperate traits

xmr-btc/src/alice.rs

@@ -3,7 +3,7 @@ use crate::{
     bitcoin::{BroadcastSignedTransaction, WatchForRawTransaction},
     bob, monero,
     monero::{CreateWalletForOutput, Transfer},
-    transport::SendReceive,
+    transport::{Receive, Send},
 };
 use anyhow::{anyhow, Result};
 use ecdsa_fun::{
@@ -21,7 +21,7 @@ pub async fn next_state<
     R: RngCore + CryptoRng,
     B: WatchForRawTransaction + BroadcastSignedTransaction,
     M: CreateWalletForOutput + Transfer,
-    T: SendReceive<Message, bob::Message>,
+    T: Send<Message> + Receive<bob::Message>,
 >(
     bitcoin_wallet: &B,
     monero_wallet: &M,

xmr-btc/src/bob.rs

@@ -6,7 +6,7 @@ use crate::{
     },
     monero,
     monero::{CheckTransfer, CreateWalletForOutput},
-    transport::SendReceive,
+    transport::{Receive, Send},
 };
 use anyhow::{anyhow, Result};
 use ecdsa_fun::{
@@ -25,7 +25,7 @@ pub async fn next_state<
     R: RngCore + CryptoRng,
     B: WatchForRawTransaction + SignTxLock + BuildTxLockPsbt + BroadcastSignedTransaction,
     M: CreateWalletForOutput + CheckTransfer,
-    T: SendReceive<Message, alice::Message>,
+    T: Send<Message> + Receive<alice::Message>,
 >(
     bitcoin_wallet: &B,
     monero_wallet: &M,

xmr-btc/src/transport.rs

@@ -2,7 +2,11 @@ use anyhow::Result;
 use async_trait::async_trait;
 
 #[async_trait]
-pub trait SendReceive<SendMsg, RecvMsg> {
+pub trait Send<SendMsg> {
     async fn send_message(&mut self, message: SendMsg) -> Result<()>;
+}
+
+#[async_trait]
+pub trait Receive<RecvMsg> {
     async fn receive_message(&mut self) -> Result<RecvMsg>;
 }

xmr-btc/tests/harness/transport.rs

@@ -4,7 +4,10 @@ use tokio::{
     stream::StreamExt,
     sync::mpsc::{Receiver, Sender},
 };
-use xmr_btc::{alice, bob, transport::SendReceive};
+use xmr_btc::{
+    alice, bob,
+    transport::{Receive, Send},
+};
 
 #[derive(Debug)]
 pub struct Transport<SendMsg, RecvMsg> {
@@ -13,7 +16,7 @@ pub struct Transport<SendMsg, RecvMsg> {
 }
 
 #[async_trait]
-impl SendReceive<alice::Message, bob::Message> for Transport<alice::Message, bob::Message> {
+impl Send<alice::Message> for Transport<alice::Message, bob::Message> {
     async fn send_message(&mut self, message: alice::Message) -> Result<()> {
         let _ = self
             .sender
@@ -22,7 +25,10 @@ impl SendReceive<alice::Message, bob::Message> for Transport<alice::Message, bob
             .map_err(|_| anyhow!("failed to send message"))?;
         Ok(())
     }
+}
 
+#[async_trait]
+impl Receive<bob::Message> for Transport<alice::Message, bob::Message> {
     async fn receive_message(&mut self) -> Result<bob::Message> {
         let message = self
             .receiver
@@ -34,7 +40,7 @@ impl SendReceive<alice::Message, bob::Message> for Transport<alice::Message, bob
 }
 
 #[async_trait]
-impl SendReceive<bob::Message, alice::Message> for Transport<bob::Message, alice::Message> {
+impl Send<bob::Message> for Transport<bob::Message, alice::Message> {
     async fn send_message(&mut self, message: bob::Message) -> Result<()> {
         let _ = self
             .sender
@@ -43,7 +49,10 @@ impl SendReceive<bob::Message, alice::Message> for Transport<bob::Message, alice
             .map_err(|_| anyhow!("failed to send message"))?;
         Ok(())
     }
+}
 
+#[async_trait]
+impl Receive<alice::Message> for Transport<bob::Message, alice::Message> {
     async fn receive_message(&mut self) -> Result<alice::Message> {
         let message = self
             .receiver