Response: add Error storage, retreival, conversion

This allows for robust creation of Response-s directly from Error-s, with error
capture for future reference, and retreival via `error() -> Option<&Error>`.

Refs: http-rs#169
Refs: http-rs/tide#546
Refs: http-rs/tide#532
Refs: http-rs/tide#452

src/response.rs

@@ -13,9 +13,9 @@ use crate::headers::{
  self, HeaderName, HeaderValue, HeaderValues, Headers, Names, ToHeaderValues, Values,
  CONTENT_TYPE,
 };
-use crate::mime::Mime;
+use crate::mime::{self, Mime};
 use crate::trailers::{self, Trailers};
-use crate::{Body, Extensions, StatusCode, Version};
+use crate::{Body, Error, Extensions, StatusCode, Version};
 
 cfg_unstable! {
  use crate::upgrade;
@@ -49,6 +49,7 @@ pin_project_lite::pin_project! {
  ext: Extensions,
  local_addr: Option<String>,
  peer_addr: Option<String>,
+ error: Option<Error>,
  }
 }
 
@@ -83,6 +84,7 @@ pin_project_lite::pin_project! {
  ext: Extensions,
  local_addr: Option<String>,
  peer_addr: Option<String>,
+ error: Option<Error>,
  }
 }
 
@@ -108,6 +110,7 @@ impl Response {
  ext: Extensions::new(),
  peer_addr: None,
  local_addr: None,
+ error: None,
  }
  }
 
@@ -136,9 +139,93 @@ impl Response {
  ext: Extensions::new(),
  peer_addr: None,
  local_addr: None,
+ // XXX(Jeremiah): should this be autogenerated on 4xx and 5xx codes?
+ error: None,
  }
  }
 
+ /// Create a new response from an `http_types::Error`.
+ ///
+ /// This will store the error in the `Response`, allowing it to later be
+ /// checked via `Response::error()`.
+ ///
+ /// If the `Error`'s status had a status code that was not a 5XX server
+ /// error code, the response body will be set to the error's message, and
+ /// the content-type header will be set to `http_types::mime::Plain`.
+ #[cfg(not(feature = "unstable"))]
+ pub fn from_error(error: Error) -> Self {
+ // Only send the message if it is a non-500 range error. All
+ // errors default to 500 by default, so sending the error
+ // body is opt-in at the call site.
+ let was_server_error = error.status().is_server_error();
+ let body = if !was_server_error {
+ Body::from_string(error.to_string())
+ } else {
+ Body::empty()
+ };
+
+ let (trailers_sender, trailers_receiver) = sync::channel(1);
+ let mut res = Self {
+ status: error.status(),
+ headers: Headers::new(),
+ version: None,
+ body,
+ trailers_sender: Some(trailers_sender),
+ trailers_receiver: Some(trailers_receiver),
+ ext: Extensions::new(),
+ peer_addr: None,
+ local_addr: None,
+ error: Some(error),
+ };
+ if !was_server_error {
+ res.set_content_type(mime::PLAIN);
+ }
+ res
+ }
+
+ /// Create a new response from an `http_types::Error`.
+ ///
+ /// This will store the error in the `Response`, allowing it to later be
+ /// checked via `Response::error()`.
+ ///
+ /// If the `Error`'s status had a status code that was not a 5XX server
+ /// error code, the response body will be set to the error's message, and
+ /// the content-type header will be set to `http_types::mime::Plain`.
+ #[cfg(feature = "unstable")]
+ pub fn from_error(error: Error) -> Self {
+ // Only send the message if it is a non-500 range error. All
+ // errors default to 500 by default, so sending the error
+ // body is opt-in at the call site.
+ let was_server_error = error.status().is_server_error();
+ let body = if !was_server_error {
+ Body::from_string(error.to_string())
+ } else {
+ Body::empty()
+ };
+
+ let (trailers_sender, trailers_receiver) = sync::channel(1);
+ let (upgrade_sender, upgrade_receiver) = sync::channel(1);
+ let mut res = Self {
+ status: error.status(),
+ headers: Headers::new(),
+ version: None,
+ body,
+ trailers_sender: Some(trailers_sender),
+ trailers_receiver: Some(trailers_receiver),
+ upgrade_sender: Some(upgrade_sender),
+ upgrade_receiver: Some(upgrade_receiver),
+ has_upgrade: false,
+ ext: Extensions::new(),
+ peer_addr: None,
+ local_addr: None,
+ error: Some(error),
+ };
+ if !was_server_error {
+ res.set_content_type(mime::PLAIN);
+ }
+ res
+ }
+
  /// Get the status
  pub fn status(&self) -> StatusCode {
  self.status
@@ -465,6 +552,16 @@ impl Response {
  self.body.is_empty()
  }
 
+ /// Returns an optional reference to the `Error` if the response was created from one, or else `None`.
+ pub fn error(&mut self) -> Option<&Error> {
+ self.error.as_ref()
+ }
+
+ /// Takes the `Error` from the response if one exists, replacing it with `None`.
+ pub fn take_error(&mut self) -> Option<Error> {
+ self.error.take()
+ }
+
  /// Get the HTTP version, if one has been set.
  ///
  /// # Examples
@@ -631,8 +728,8 @@ impl Response {
 }
 
 impl Clone for Response {
- /// Clone the response, resolving the body to `Body::empty()` and removing
- /// extensions.
+ /// Clone the response, resolving the body to `Body::empty()`, removing
+ /// extensions, and unsetting any `Error`.
  fn clone(&self) -> Self {
  Self {
  status: self.status.clone(),
@@ -650,6 +747,7 @@ impl Clone for Response {
  ext: Extensions::new(),
  peer_addr: self.peer_addr.clone(),
  local_addr: self.local_addr.clone(),
+ error: None,
  }
  }
 }
@@ -722,6 +820,12 @@ impl Index<&str> for Response {
  }
 }
 
+impl From<Error> for Response {
+ fn from(e: Error) -> Self {
+ Self::from_error(e)
+ }
+}
+
 impl From<StatusCode> for Response {
  fn from(s: StatusCode) -> Self {
  Response::new(s)

tests/error.rs

@@ -1,4 +1,4 @@
-use http_types::{bail, ensure, ensure_eq, Error, StatusCode};
+use http_types::{bail, ensure, ensure_eq, Error, StatusCode, Response};
 use std::io;
 
 #[test]
@@ -71,3 +71,23 @@ fn option_ext() {
  let err = res.unwrap_err();
  assert_eq!(err.status(), StatusCode::NotFound);
 }
+
+#[async_std::test]
+async fn to_response() {
+ let msg = "This is an error";
+
+ let error = Error::from_str(StatusCode::NotFound, msg);
+ let mut res = Response::from_error(error);
+
+ assert!(res.error().is_some());
+ // Ensure we did not consume the error
+ assert!(res.error().is_some()); 
+
+ assert_eq!(res.error().unwrap().status(), StatusCode::NotFound);
+ assert_eq!(res.error().unwrap().to_string(), msg);
+
+ res.take_error();
+ assert!(res.error().is_none());
+
+ assert_eq!(res.body_string().await.unwrap(), msg);
+}