From 7b61c63ece4384f75fa41f6c052b3d9e506ff3aa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Fri, 3 Sep 2021 13:26:10 +0900
Subject: [PATCH] Handle stderr

---
 helix-dap/src/client.rs    |  8 ++++++--
 helix-dap/src/transport.rs | 28 ++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/helix-dap/src/client.rs b/helix-dap/src/client.rs
index 5d9916c92..9f2740022 100644
--- a/helix-dap/src/client.rs
+++ b/helix-dap/src/client.rs
@@ -62,10 +62,11 @@ impl Client {
     pub fn streams(
         rx: Box<dyn AsyncBufRead + Unpin + Send>,
         tx: Box<dyn AsyncWrite + Unpin + Send>,
+        err: Option<Box<dyn AsyncBufRead + Unpin + Send>>,
         id: usize,
         process: Option<Child>,
     ) -> Result<(Self, UnboundedReceiver<Payload>)> {
-        let (server_rx, server_tx) = Transport::start(rx, tx, id);
+        let (server_rx, server_tx) = Transport::start(rx, tx, err, id);
         let (client_rx, client_tx) = unbounded_channel();
 
         let client = Self {
@@ -92,7 +93,7 @@ impl Client {
     ) -> Result<(Self, UnboundedReceiver<Payload>)> {
         let stream = TcpStream::connect(addr).await?;
         let (rx, tx) = stream.into_split();
-        Self::streams(Box::new(BufReader::new(rx)), Box::new(tx), id, None)
+        Self::streams(Box::new(BufReader::new(rx)), Box::new(tx), None, id, None)
     }
 
     pub fn stdio(
@@ -113,10 +114,12 @@ impl Client {
         // TODO: do we need bufreader/writer here? or do we use async wrappers on unblock?
         let writer = BufWriter::new(process.stdin.take().expect("Failed to open stdin"));
         let reader = BufReader::new(process.stdout.take().expect("Failed to open stdout"));
+        let errors = BufReader::new(process.stderr.take().expect("Failed to open stderr"));
 
         Self::streams(
             Box::new(BufReader::new(reader)),
             Box::new(writer),
+            Some(Box::new(BufReader::new(errors))),
             id,
             Some(process),
         )
@@ -167,6 +170,7 @@ impl Client {
         Self::streams(
             Box::new(BufReader::new(rx)),
             Box::new(tx),
+            None,
             id,
             Some(process),
         )
diff --git a/helix-dap/src/transport.rs b/helix-dap/src/transport.rs
index afb7694d5..a20dfbe17 100644
--- a/helix-dap/src/transport.rs
+++ b/helix-dap/src/transport.rs
@@ -53,6 +53,7 @@ impl Transport {
     pub fn start(
         server_stdout: Box<dyn AsyncBufRead + Unpin + Send>,
         server_stdin: Box<dyn AsyncWrite + Unpin + Send>,
+        server_stderr: Option<Box<dyn AsyncBufRead + Unpin + Send>>,
         id: usize,
     ) -> (UnboundedReceiver<Payload>, UnboundedSender<Request>) {
         let (client_tx, rx) = unbounded_channel();
@@ -67,6 +68,9 @@ impl Transport {
 
         tokio::spawn(Self::recv(transport.clone(), server_stdout, client_tx));
         tokio::spawn(Self::send(transport, server_stdin, client_rx));
+        if let Some(stderr) = server_stderr {
+            tokio::spawn(Self::err(stderr));
+        }
 
         (rx, tx)
     }
@@ -117,6 +121,17 @@ impl Transport {
         Ok(output?)
     }
 
+    async fn recv_server_error(
+        err: &mut (impl AsyncBufRead + Unpin + Send),
+        buffer: &mut String,
+    ) -> Result<()> {
+        buffer.truncate(0);
+        err.read_line(buffer).await?;
+        error!("err <- {}", buffer);
+
+        Ok(())
+    }
+
     async fn send_payload_to_server(
         &self,
         server_stdin: &mut Box<dyn AsyncWrite + Unpin + Send>,
@@ -243,4 +258,17 @@ impl Transport {
                 .unwrap()
         }
     }
+
+    async fn err(mut server_stderr: Box<dyn AsyncBufRead + Unpin + Send>) {
+        let mut recv_buffer = String::new();
+        loop {
+            match Self::recv_server_error(&mut server_stderr, &mut recv_buffer).await {
+                Ok(_) => {}
+                Err(err) => {
+                    error!("err: <- {:?}", err);
+                    break;
+                }
+            }
+        }
+    }
 }