add middleware composition tests (#2375)

actix-http/src/body/message_body.rs

@@ -11,8 +11,6 @@ use bytes::{Bytes, BytesMut};
 use futures_core::ready;
 use pin_project_lite::pin_project;
 
-use crate::error::Error;
-
 use super::BodySize;
 
 /// An interface for response bodies.
@@ -47,7 +45,6 @@ impl MessageBody for () {
 impl<B> MessageBody for Box<B>
 where
     B: MessageBody + Unpin,
-    B::Error: Into<Error>,
 {
     type Error = B::Error;
 
@@ -66,7 +63,6 @@ where
 impl<B> MessageBody for Pin<Box<B>>
 where
     B: MessageBody,
-    B::Error: Into<Error>,
 {
     type Error = B::Error;
 

actix-http/src/encoding/encoder.rs

@@ -29,7 +29,7 @@ use crate::{
         header::{ContentEncoding, CONTENT_ENCODING},
         HeaderValue, StatusCode,
     },
-    Error, ResponseHead,
+    ResponseHead,
 };
 
 use super::Writer;
@@ -107,7 +107,6 @@ enum EncoderBody<B> {
 impl<B> MessageBody for EncoderBody<B>
 where
     B: MessageBody,
-    B::Error: Into<Error>,
 {
     type Error = EncoderError<B::Error>;
 
@@ -142,7 +141,6 @@ where
 impl<B> MessageBody for Encoder<B>
 where
     B: MessageBody,
-    B::Error: Into<Error>,
 {
     type Error = EncoderError<B::Error>;
 

actix-http/src/h1/utils.rs

@@ -65,7 +65,9 @@ where
                     let next =
                         match this.body.as_mut().as_pin_mut().unwrap().poll_next(cx) {
                             Poll::Ready(Some(Ok(item))) => Poll::Ready(Some(item)),
-                            Poll::Ready(Some(Err(err))) => return Poll::Ready(Err(err.into())),
+                            Poll::Ready(Some(Err(err))) => {
+                                return Poll::Ready(Err(err.into()))
+                            }
                             Poll::Ready(None) => Poll::Ready(None),
                             Poll::Pending => Poll::Pending,
                         };