From 740654e55d2bb2f50709f20fb4054a5504d8c2fb Mon Sep 17 00:00:00 2001
From: Sean McArthur <sean@seanmonstar.com>
Date: Fri, 11 Mar 2022 17:44:06 -0800
Subject: [PATCH] refactor(error): improve error message when user body ends
 early

---
 src/error.rs           | 10 +++++-----
 src/proto/h1/conn.rs   |  6 ++----
 src/proto/h1/encode.rs | 12 ++++++++++--
 3 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/src/error.rs b/src/error.rs
index 265f9172dc..20acf3a7a5 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -53,8 +53,6 @@ pub(super) enum Kind {
     /// Error while writing a body to connection.
     #[cfg(any(feature = "http1", feature = "http2"))]
     BodyWrite,
-    /// The body write was aborted.
-    BodyWriteAborted,
     /// Error calling AsyncWrite::shutdown()
     #[cfg(feature = "http1")]
     Shutdown,
@@ -96,6 +94,8 @@ pub(super) enum User {
     /// Error calling user's HttpBody::poll_data().
     #[cfg(any(feature = "http1", feature = "http2"))]
     Body,
+    /// The user aborted writing of the outgoing body.
+    BodyWriteAborted,
     /// Error calling user's MakeService.
     #[cfg(any(feature = "http1", feature = "http2"))]
     #[cfg(feature = "server")]
@@ -193,7 +193,7 @@ impl Error {
 
     /// Returns true if the body write was aborted.
     pub fn is_body_write_aborted(&self) -> bool {
-        matches!(self.inner.kind, Kind::BodyWriteAborted)
+        matches!(self.inner.kind, Kind::User(User::BodyWriteAborted))
     }
 
     /// Returns true if the error was caused by a timeout.
@@ -305,7 +305,7 @@ impl Error {
     }
 
     pub(super) fn new_body_write_aborted() -> Error {
-        Error::new(Kind::BodyWriteAborted)
+        Error::new(Kind::User(User::BodyWriteAborted))
     }
 
     fn new_user(user: User) -> Error {
@@ -444,7 +444,6 @@ impl Error {
             Kind::Body => "error reading a body from connection",
             #[cfg(any(feature = "http1", feature = "http2"))]
             Kind::BodyWrite => "error writing a body to connection",
-            Kind::BodyWriteAborted => "body write aborted",
             #[cfg(feature = "http1")]
             Kind::Shutdown => "error shutting down connection",
             #[cfg(feature = "http2")]
@@ -454,6 +453,7 @@ impl Error {
 
             #[cfg(any(feature = "http1", feature = "http2"))]
             Kind::User(User::Body) => "error from user's HttpBody stream",
+            Kind::User(User::BodyWriteAborted) => "user body write aborted",
             #[cfg(any(feature = "http1", feature = "http2"))]
             #[cfg(feature = "server")]
             Kind::User(User::MakeService) => "error from user's MakeService",
diff --git a/src/proto/h1/conn.rs b/src/proto/h1/conn.rs
index e09a6e3da1..66b2cdacc3 100644
--- a/src/proto/h1/conn.rs
+++ b/src/proto/h1/conn.rs
@@ -686,10 +686,8 @@ where
                             Writing::KeepAlive
                         }
                     }
-                    Err(_not_eof) => {
-                        res = Err(crate::Error::new_user_body(
-                            crate::Error::new_body_write_aborted(),
-                        ));
+                    Err(not_eof) => {
+                        res = Err(crate::Error::new_body_write_aborted().with(not_eof));
                         Writing::Closed
                     }
                 }
diff --git a/src/proto/h1/encode.rs b/src/proto/h1/encode.rs
index 703f4f4fb9..f0aa261a4f 100644
--- a/src/proto/h1/encode.rs
+++ b/src/proto/h1/encode.rs
@@ -22,7 +22,7 @@ pub(crate) struct EncodedBuf<B> {
 }
 
 #[derive(Debug)]
-pub(crate) struct NotEof;
+pub(crate) struct NotEof(u64);
 
 #[derive(Debug, PartialEq, Clone)]
 enum Kind {
@@ -98,7 +98,7 @@ impl Encoder {
             })),
             #[cfg(feature = "server")]
             Kind::CloseDelimited => Ok(None),
-            Kind::Length(_) => Err(NotEof),
+            Kind::Length(n) => Err(NotEof(n)),
         }
     }
 
@@ -351,6 +351,14 @@ impl<B: Buf> From<Chain<Chain<ChunkSize, B>, StaticBuf>> for EncodedBuf<B> {
     }
 }
 
+impl fmt::Display for NotEof {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "early end, expected {} more bytes", self.0)
+    }
+}
+
+impl std::error::Error for NotEof {}
+
 #[cfg(test)]
 mod tests {
     use bytes::BufMut;