Fix doc(cfg)s (#765)

* Use automatic doc(cfg) attributes where possible

* Add missing feature documentation

* Replace redundant cfg attribute with doc(cfg)

* Remove non-existent feature from package.metadata.playground.features

* Add missing cfg's on rejection types

axum/Cargo.toml

@@ -83,10 +83,9 @@ rustdoc-args = ["--cfg", "docsrs"]
 
 [package.metadata.playground]
 features = [
-  "http1",
-  "http2",
-  "json",
-  "multipart",
-  "tower",
-  "ws",
+    "http1",
+    "http2",
+    "json",
+    "multipart",
+    "ws",
 ]

axum/src/extract/mod.rs

@@ -9,7 +9,6 @@ pub mod path;
 pub mod rejection;
 
 #[cfg(feature = "ws")]
-#[cfg_attr(docsrs, doc(cfg(feature = "ws")))]
 pub mod ws;
 
 mod content_length_limit;
@@ -43,25 +42,20 @@ pub use self::{
 pub use crate::Json;
 
 #[cfg(feature = "multipart")]
-#[cfg_attr(docsrs, doc(cfg(feature = "multipart")))]
 pub mod multipart;
 
 #[cfg(feature = "multipart")]
-#[cfg_attr(docsrs, doc(cfg(feature = "multipart")))]
 #[doc(inline)]
 pub use self::multipart::Multipart;
 
 #[cfg(feature = "ws")]
-#[cfg_attr(docsrs, doc(cfg(feature = "ws")))]
 #[doc(inline)]
 pub use self::ws::WebSocketUpgrade;
 
 #[cfg(feature = "headers")]
-#[cfg_attr(docsrs, doc(cfg(feature = "headers")))]
 mod typed_header;
 
 #[cfg(feature = "headers")]
-#[cfg_attr(docsrs, doc(cfg(feature = "headers")))]
 #[doc(inline)]
 pub use self::typed_header::TypedHeader;
 

axum/src/extract/multipart.rs

@@ -44,6 +44,7 @@ use std::{
 ///
 /// For security reasons its recommended to combine this with
 /// [`ContentLengthLimit`](super::ContentLengthLimit) to limit the size of the request payload.
+#[cfg_attr(docsrs, doc(cfg(feature = "multipart")))]
 #[derive(Debug)]
 pub struct Multipart {
     inner: multer::Multipart<'static>,

axum/src/extract/rejection.rs

@@ -18,9 +18,11 @@ define_rejection! {
     pub struct InvalidJsonBody(Error);
 }
 
+#[cfg(feature = "json")]
 define_rejection! {
     #[status = UNSUPPORTED_MEDIA_TYPE]
     #[body = "Expected request with `Content-Type: application/json`"]
+    #[cfg_attr(docsrs, doc(cfg(feature = "json")))]
     /// Rejection type for [`Json`](super::Json) used if the `Content-Type`
     /// header is missing.
     pub struct MissingJsonContentType;
@@ -243,5 +245,4 @@ where
 }
 
 #[cfg(feature = "headers")]
-#[cfg_attr(docsrs, doc(cfg(feature = "headers")))]
 pub use super::typed_header::{TypedHeaderRejection, TypedHeaderRejectionReason};

axum/src/extract/typed_header.rs

@@ -30,7 +30,6 @@ use std::ops::Deref;
 /// # axum::Server::bind(&"".parse().unwrap()).serve(app.into_make_service()).await.unwrap();
 /// # };
 /// ```
-#[cfg(feature = "headers")]
 #[cfg_attr(docsrs, doc(cfg(feature = "headers")))]
 #[derive(Debug, Clone, Copy)]
 pub struct TypedHeader<T>(pub T);
@@ -77,7 +76,6 @@ impl<T> Deref for TypedHeader<T> {
 
 /// Rejection used for [`TypedHeader`](super::TypedHeader).
 #[cfg(feature = "headers")]
-#[cfg_attr(docsrs, doc(cfg(feature = "headers")))]
 #[derive(Debug)]
 pub struct TypedHeaderRejection {
     name: &'static http::header::HeaderName,

axum/src/extract/ws.rs

@@ -103,6 +103,7 @@ use tokio_tungstenite::{
 ///
 /// See the [module docs](self) for an example.
 #[derive(Debug)]
+#[cfg_attr(docsrs, doc(cfg(feature = "ws")))]
 pub struct WebSocketUpgrade {
     config: WebSocketConfig,
     /// The chosen protocol sent in the `Sec-WebSocket-Protocol` header of the response.

axum/src/lib.rs

@@ -386,7 +386,7 @@
 #![deny(unreachable_pub, private_in_public)]
 #![allow(elided_lifetimes_in_paths, clippy::type_complexity)]
 #![forbid(unsafe_code)]
-#![cfg_attr(docsrs, feature(doc_cfg))]
+#![cfg_attr(docsrs, feature(doc_auto_cfg, doc_cfg))]
 #![cfg_attr(test, allow(clippy::float_cmp))]
 
 #[macro_use]

axum/src/response/sse.rs

@@ -210,8 +210,7 @@ impl Event {
     ///
     /// [`MessageEvent`'s data field]: https://developer.mozilla.org/en-US/docs/Web/API/MessageEvent/data
     #[cfg(feature = "json")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "json")))]
-    pub fn json_data<T>(mut self, data: T) -> Result<Event, serde_json::Error>
+    pub fn json_data<T>(mut self, data: T) -> serde_json::Result<Event>
     where
         T: serde::Serialize,
     {