feat(client): include connection info in Client::send_request errors (#2749)

Author: nox

src/client/client.rs

@@ -251,7 +251,7 @@ where
             if req.version() == Version::HTTP_2 {
                 warn!("Connection is HTTP/1, but request requires HTTP/2");
                 return Err(ClientError::Normal(
-                    crate::Error::new_user_unsupported_version(),
+                    crate::Error::new_user_unsupported_version().with_client_connect_info(pooled.conn_info.clone()),
                 ));
             }
 
@@ -281,18 +281,20 @@ where
             authority_form(req.uri_mut());
         }
 
-        let fut = pooled
-            .send_request_retryable(req)
-            .map_err(ClientError::map_with_reused(pooled.is_reused()));
+        let mut res = match pooled.send_request_retryable(req).await {
+            Err((err, orig_req)) => {
+                return Err(ClientError::map_with_reused(pooled.is_reused())((
+                    err.with_client_connect_info(pooled.conn_info.clone()),
+                    orig_req,
+                )));
+            }
+            Ok(res) => res,
+        };
 
         // If the Connector included 'extra' info, add to Response...
-        let extra_info = pooled.conn_info.extra.clone();
-        let fut = fut.map_ok(move |mut res| {
-            if let Some(extra) = extra_info {
-                extra.set(res.extensions_mut());
-            }
-            res
-        });
+        if let Some(extra) = &pooled.conn_info.extra {
+            extra.set(res.extensions_mut());
+        }
 
         // As of futures@0.1.21, there is a race condition in the mpsc
         // channel, such that sending when the receiver is closing can
@@ -302,11 +304,9 @@ where
         // To counteract this, we must check if our senders 'want' channel
         // has been closed after having tried to send. If so, error out...
         if pooled.is_closed() {
-            return fut.await;
+            return Ok(res);
         }
 
-        let mut res = fut.await?;
-
         // If pooled is HTTP/2, we can toss this reference immediately.
         //
         // when pooled is dropped, it will try to insert back into the

src/error.rs

@@ -1,4 +1,7 @@
 //! Error and Result module.
+
+#[cfg(all(feature = "client", any(feature = "http1", feature = "http2")))]
+use crate::client::connect::Connected;
 use std::error::Error as StdError;
 use std::fmt;
 
@@ -15,6 +18,8 @@ pub struct Error {
 struct ErrorImpl {
     kind: Kind,
     cause: Option<Cause>,
+    #[cfg(all(feature = "client", any(feature = "http1", feature = "http2")))]
+    connect_info: Option<Connected>,
 }
 
 #[derive(Debug)]
@@ -210,9 +215,20 @@ impl Error {
         self.inner.cause
     }
 
+    /// Returns the info of the client connection on which this error occurred.
+    #[cfg(all(feature = "client", any(feature = "http1", feature = "http2")))]
+    pub fn client_connect_info(&self) -> Option<&Connected> {
+        self.inner.connect_info.as_ref()
+    }
+
     pub(super) fn new(kind: Kind) -> Error {
         Error {
-            inner: Box::new(ErrorImpl { kind, cause: None }),
+            inner: Box::new(ErrorImpl {
+                kind,
+                cause: None,
+                #[cfg(all(feature = "client", any(feature = "http1", feature = "http2")))]
+                connect_info: None,
+            }),
         }
     }
 
@@ -221,6 +237,12 @@ impl Error {
         self
     }
 
+    #[cfg(all(feature = "client", any(feature = "http1", feature = "http2")))]
+    pub(super) fn with_client_connect_info(mut self, connect_info: Connected) -> Error {
+        self.inner.connect_info = Some(connect_info);
+        self
+    }
+
     #[cfg(any(all(feature = "http1", feature = "server"), feature = "ffi"))]
     pub(super) fn kind(&self) -> &Kind {
         &self.inner.kind