I made le test pass

src/lib.rs

@@ -5,7 +5,9 @@ extern crate multi_tcp;
 extern crate serde;
 extern crate serde_json;
 
-use std::io;
+use serde::Deserialize;
+use std::fmt;
+use std::io::{self, Read};
 use std::convert;
 use std::collections::HashMap;
 use std::net::{
@@ -36,7 +38,10 @@ pub enum Error {
 
 impl convert::From<serde_json::Error> for Error {
     fn from(err: serde_json::Error) -> Error {
-        Error::Json(err)
+        match err {
+            serde_json::Error::IoError(err) => Error::Io(err),
+            err => Error::Json(err),
+        }
     }
 }
 
@@ -55,21 +60,27 @@ impl<T> convert::From<sync::mpsc::SendError<T>> for Error {
 pub type Result<T> = std::result::Result<T, Error>;
 
 pub fn handle_conn<F, Request, Reply>(
-    mut conn: TcpStream,
+    mut stream: TcpStream,
     f: F) -> Result<()>
-    where Request: serde::de::Deserialize,
-          Reply: serde::ser::Serialize,
+    where Request: fmt::Debug + serde::de::Deserialize,
+          Reply: fmt::Debug + serde::ser::Serialize,
           F: 'static + Serve<Request, Reply>
 {
-    let request: Request = try!(serde_json::from_reader(&mut conn));
-    let response = try!(f.serve(&request));
-    try!(serde_json::to_writer(&mut conn, &response));
+    let read_stream = try!(stream.try_clone());
+    let mut de = serde_json::Deserializer::new(read_stream.bytes());
+    let request_packet: Packet<Request> = try!(Packet::deserialize(&mut de));
+    let reply = try!(f.serve(&request_packet.message));
+    let reply_packet = Packet{
+        id: request_packet.id,
+        message: reply,
+    };
+    try!(serde_json::to_writer(&mut stream, &reply_packet));
     Ok(())
 }
 
 pub fn serve<F, Request, Reply>(listener: TcpListener, f: F) -> Error
-    where Request: serde::de::Deserialize,
-          Reply: serde::ser::Serialize,
+    where Request: fmt::Debug + serde::de::Deserialize,
+          Reply: fmt::Debug + serde::ser::Serialize,
           F: 'static + Serve<Request, Reply>,
 {
     for conn in listener.incoming() {
@@ -77,7 +88,6 @@ pub fn serve<F, Request, Reply>(listener: TcpListener, f: F) -> Error
             Err(err) => return convert::From::from(err),
             Ok(c) => c,
         };
-        println!("received connection");
         let f = f.clone();
         thread::spawn(move || {
             if let Err(err) = handle_conn(conn, f) {
@@ -92,7 +102,7 @@ pub trait Serve<Request, Reply> : Sync + Send + Clone {
     fn serve(&self, request: &Request) -> io::Result<Reply>;
 }
 
-#[derive(Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 struct Packet<T> {
     id: u64,
     message: T,
@@ -126,7 +136,7 @@ fn receiver<Reply>(messages: Receiver<ReceiverMessage<Reply>>) -> Result<()> {
 
 pub struct Client<Request, Reply> {
     next_id: Mutex<u64>,
-    writer: multi_tcp::MultiStream<Packet<Request>, serde_json::Error>,
+    writer: multi_tcp::MultiStream<Packet<Request>, Error>,
     handles_tx: SyncSender<ReceiverMessage<Reply>>,
 }
 
@@ -136,20 +146,16 @@ impl<Request, Reply> Client<Request, Reply>
 {
     pub fn new(stream: TcpStream) -> Result<Self> {
         let (handles_tx, receiver_rx) = sync_channel(0);
-        let writer = multi_tcp::MultiStream::with_sync_sender(
+        let writer: multi_tcp::MultiStream<Packet<Request>, Error>
+            = multi_tcp::MultiStream::with_sync_sender(
             stream,
-            |stream, packet: &Packet<Request>| {
-                try!(serde_json::to_writer(stream, &packet.id));
-                try!(serde_json::to_writer(stream, &packet.message));
+            |stream: &mut TcpStream, packet: &Packet<Request>| {
+                try!(serde_json::to_writer(stream, packet));
                 Ok(())
             },
-            |stream| {
-                let id = try!(serde_json::from_reader(stream));
-                let reply = try!(serde_json::from_reader(stream));
-                Ok(ReceiverMessage::Packet(Packet{
-                    id: id,
-                    message: reply,
-                }))
+            |mut stream| {
+                let packet = try!(serde_json::from_reader(&mut stream));
+                Ok(ReceiverMessage::Packet(packet))
             },
             handles_tx.clone());
         thread::spawn(move || receiver(receiver_rx));
@@ -169,17 +175,14 @@ impl<Request, Reply> Client<Request, Reply>
     pub fn rpc(&self, request: &Request) -> Result<Reply> {
         let (tx, rx) = channel();
         let id = self.get_next_id();
-        println!("indicate that we're weaiting");
         try!(self.handles_tx.send(ReceiverMessage::Handle(Handle{
             id: id,
             sender: tx,
         })));
-        println!("write the request to the wire");
         try!(self.writer.write(Packet{
             id: id,
             message: request.clone(),
         }));
-        println!("wait for the response");
         Ok(rx.recv().unwrap())
     }
 }
@@ -220,13 +223,8 @@ mod test {
     #[test]
     fn test() {
         let (client_stream, server_streams) = pair();
-        println!("starting server!");
-        thread::spawn(|| {
-            serve(server_streams, Server)
-        });
-        println!("making client");
+        thread::spawn(|| serve(server_streams, Server));
         let client: Client<Request, Reply> = Client::new(client_stream).unwrap();
-        println!("hi there");
         assert_eq!(Reply::Increment, client.rpc(&Request::Increment).unwrap());
     }
 }

src/multi_tcp/src/lib.rs

@@ -15,7 +15,7 @@ fn read<T, F, E>(mut stream: TcpStream, decode: F, tx: SyncSender<T>)
           E: fmt::Debug + Send + 'static
 {
     loop {
-        let t = decode(&mut stream).unwrap();
+        let t = decode(&mut stream).expect("I couldn't do the thing");
         if let Err(_) = tx.send(t) {
             break;
         }
@@ -41,7 +41,8 @@ fn write<T, F, E>(mut stream: TcpStream, encode: F) -> Sender<SendHelper<T, E>>
                     break;
                 }
             };
-            helper.result.send(encode(&mut stream, &helper.value)).unwrap();
+            helper.result.send(encode(&mut stream, &helper.value))
+                .expect("died trying to send the result to the helper");
         }
     });
     tx