move client logic into one async fn

src/main.rs

@@ -1,10 +1,11 @@
+// TODO: try doing without this every now and then, hopefully it's eventually unnecessary
+#![type_length_limit="1272053"]
 #[macro_use]
 extern crate log;
 
 use anyhow::{Context, Result};
 use future::ready;
 use futures::prelude::*;
-use futures::try_join;
 use net::{server::greet, ClientMessage, ServerMessage};
 use serde_json::{from_str, to_string};
 use std::net::ToSocketAddrs;
@@ -58,7 +59,7 @@ async fn main() -> Result<()> {
 async fn handle_socket(websocket: WebSocket) -> Result<()> {
     let (sink, source) = websocket.split();
 
-    let mut sink = sink.with(|msg: ServerMessage| {
+    let sink = sink.with(|msg: ServerMessage| {
         ready(
             to_string(&msg)
                 .context("JSON encoding shouldn't fail")
@@ -66,9 +67,7 @@ async fn handle_socket(websocket: WebSocket) -> Result<()> {
         )
     });
 
-    greet(&mut sink).await?;
-
-    let mut source = source.map_err(Into::into).try_filter_map(|msg| {
+    let source = source.map_err(Into::into).try_filter_map(|msg| {
         ready(match msg.to_str() {
             Ok(json) => from_str::<ClientMessage>(json)
                 .context("Parsing JSON")
@@ -80,14 +79,5 @@ async fn handle_socket(websocket: WebSocket) -> Result<()> {
         })
     });
 
-    let input_task = async {
-        loop {
-            match source.next().await {
-                Some(Ok(msg)) => debug!("Client message: {:?}", &msg),
-                Some(Err(error)) => return Err(error),
-                None => break Ok(()),
-            }
-        }
-    };
-    try_join!(input_task).map(|((),)| ())
+    run_client(source, sink).await
 }

src/net/server.rs

@@ -1,11 +1,13 @@
-use anyhow::{Context, Error, Result};
 use super::*;
-use futures::prelude::*;
+use anyhow::{Context, Error, Result};
+use futures::{channel::mpsc::*, future::try_join, lock::Mutex, prelude::*};
 use serde_json::json;
+use std::sync::Arc;
 use stream::iter;
 
 pub async fn greet<T>(sink: &mut T) -> Result<()>
-where T: Sink<ServerMessage, Error = Error> + Unpin
+where
+    T: Sink<ServerMessage, Error = Error> + Unpin,
 {
     let mut greeting = iter(vec![
         ServerMessage::Meta {
@@ -14,12 +16,33 @@ where T: Sink<ServerMessage, Error = Error> + Unpin
                 helo: Some("Dedicated base2020 server".into()),
             },
         },
-        ServerMessage::SetState {
-            u: 0,
-            s: json!({}),
-        },
+        ServerMessage::SetState { u: 0, s: json!({}) },
     ])
     .map(Ok);
 
-    sink.send_all(&mut greeting).await.context("Greeting client")
+    sink.send_all(&mut greeting)
+        .await
+        .context("Greeting client")
+}
+
+pub async fn run_client<I, O>(mut source: I, mut sink: O) -> Result<()>
+where
+    I: Stream<Item = Result<ClientMessage, Error>> + Unpin,
+    O: Sink<ServerMessage, Error = Error> + Unpin,
+{
+    let output_task = async {
+        greet(&mut sink).await?;
+        Ok::<(), Error>(())
+    };
+
+    let input_task = async {
+        loop {
+            match source.next().await {
+                Some(Ok(msg)) => debug!("Client message: {:?}", &msg),
+                Some(Err(error)) => return Err(error),
+                None => break Ok(()),
+            }
+        }
+    };
+    try_join(output_task, input_task).await.map(|((), ())| ())
 }