Type safe state inheritance (#1532)

* Make state type safe

* fix examples

* remove unnecessary `#[track_caller]`s

* Router::into_service -> Router::with_state

* fixup docs

* macro docs

* add missing docs

* fix examples

* format

* changelog

* Update trybuild tests

* Make sure fallbacks are still inherited for opaque services (#1540)

* Document nesting routers with different state

* fix leftover conflicts

axum-macros/Cargo.toml

@@ -25,7 +25,7 @@ syn = { version = "1.0", features = [
 ] }
 
 [dev-dependencies]
-axum = { path = "../axum", version = "0.6.0-rc.2", features = ["headers"] }
+axum = { path = "../axum", version = "0.6.0-rc.2", features = ["headers", "macros"] }
 axum-extra = { path = "../axum-extra", version = "0.4.0-rc.1", features = ["typed-routing", "cookie-private"] }
 rustversion = "1.0"
 serde = { version = "1.0", features = ["derive"] }

axum-macros/src/lib.rs

@@ -181,7 +181,6 @@ use from_request::Trait::{FromRequest, FromRequestParts};
 /// rejection type with `#[from_request(rejection(YourType))]`:
 ///
 /// ```
-/// use axum_macros::FromRequest;
 /// use axum::{
 ///     extract::{
 ///         rejection::{ExtensionRejection, StringRejection},
@@ -463,8 +462,7 @@ pub fn derive_from_request_parts(item: TokenStream) -> TokenStream {
 /// As the error message says, handler function needs to be async.
 ///
 /// ```
-/// use axum::{routing::get, Router};
-/// use axum_macros::debug_handler;
+/// use axum::{routing::get, Router, debug_handler};
 ///
 /// #[tokio::main]
 /// async fn main() {
@@ -493,8 +491,7 @@ pub fn derive_from_request_parts(item: TokenStream) -> TokenStream {
 /// To work around that the request body type can be customized like so:
 ///
 /// ```
-/// use axum::{body::BoxBody, http::Request};
-/// # use axum_macros::debug_handler;
+/// use axum::{body::BoxBody, http::Request, debug_handler};
 ///
 /// #[debug_handler(body = BoxBody)]
 /// async fn handler(request: Request<BoxBody>) {}
@@ -506,8 +503,7 @@ pub fn derive_from_request_parts(item: TokenStream) -> TokenStream {
 /// [`axum::extract::State`] argument:
 ///
 /// ```
-/// use axum::extract::State;
-/// # use axum_macros::debug_handler;
+/// use axum::{debug_handler, extract::State};
 ///
 /// #[debug_handler]
 /// async fn handler(
@@ -523,8 +519,7 @@ pub fn derive_from_request_parts(item: TokenStream) -> TokenStream {
 /// customize the state type you can set it with `#[debug_handler(state = ...)]`:
 ///
 /// ```
-/// use axum::extract::{State, FromRef};
-/// # use axum_macros::debug_handler;
+/// use axum::{debug_handler, extract::{State, FromRef}};
 ///
 /// #[debug_handler(state = AppState)]
 /// async fn handler(
@@ -579,8 +574,11 @@ pub fn derive_typed_path(input: TokenStream) -> TokenStream {
 /// # Example
 ///
 /// ```
-/// use axum_macros::FromRef;
-/// use axum::{Router, routing::get, extract::State};
+/// use axum::{
+///     Router,
+///     routing::get,
+///     extract::{State, FromRef},
+/// };
 ///
 /// #
 /// # type AuthToken = String;
@@ -605,8 +603,10 @@ pub fn derive_typed_path(input: TokenStream) -> TokenStream {
 ///     database_pool,
 /// };
 ///
-/// let app = Router::with_state(state).route("/", get(handler).post(other_handler));
-/// # let _: Router<AppState> = app;
+/// let app = Router::new()
+///     .route("/", get(handler).post(other_handler))
+///     .with_state(state);
+/// # let _: axum::routing::RouterService = app;
 /// ```
 ///
 /// [`FromRef`]: https://docs.rs/axum/latest/axum/extract/trait.FromRef.html

axum-macros/tests/from_ref/pass/basic.rs

@@ -1,5 +1,4 @@
-use axum_macros::FromRef;
-use axum::{Router, routing::get, extract::State};
+use axum::{Router, routing::get, extract::{State, FromRef}};
 
 // This will implement `FromRef` for each field in the struct.
 #[derive(Clone, FromRef)]
@@ -15,5 +14,7 @@ fn main() {
         auth_token: Default::default(),
     };
 
-    let _: Router<AppState> = Router::with_state(state).route("/", get(handler));
+    let _: axum::routing::RouterService = Router::new()
+        .route("/", get(handler))
+        .with_state(state);
 }

axum-macros/tests/from_request/fail/parts_extracting_body.rs

@@ -1,5 +1,4 @@
 use axum::{extract::FromRequestParts, response::Response};
-use axum_macros::FromRequestParts;
 
 #[derive(FromRequestParts)]
 struct Extractor {

axum-macros/tests/from_request/fail/parts_extracting_body.stderr

@@ -1,7 +1,7 @@
 error[E0277]: the trait bound `String: FromRequestParts<S>` is not satisfied
- --> tests/from_request/fail/parts_extracting_body.rs:6:11
+ --> tests/from_request/fail/parts_extracting_body.rs:5:11
   |
-6 |     body: String,
+5 |     body: String,
   |           ^^^^^^ the trait `FromRequestParts<S>` is not implemented for `String`
   |
   = help: the following other types implement trait `FromRequestParts<S>`:

axum-macros/tests/from_request/pass/container.rs

@@ -3,7 +3,6 @@ use axum::{
     extract::{FromRequest, Json},
     response::Response,
 };
-use axum_macros::FromRequest;
 use serde::Deserialize;
 
 #[derive(Deserialize, FromRequest)]

axum-macros/tests/from_request/pass/container_parts.rs

@@ -2,7 +2,6 @@ use axum::{
     extract::{FromRequestParts, Extension},
     response::Response,
 };
-use axum_macros::FromRequestParts;
 
 #[derive(Clone, FromRequestParts)]
 #[from_request(via(Extension))]

axum-macros/tests/from_request/pass/named.rs

@@ -4,7 +4,6 @@ use axum::{
     response::Response,
     headers::{self, UserAgent},
 };
-use axum_macros::FromRequest;
 
 #[derive(FromRequest)]
 struct Extractor {

axum-macros/tests/from_request/pass/named_parts.rs

@@ -3,7 +3,6 @@ use axum::{
     headers::{self, UserAgent},
     response::Response,
 };
-use axum_macros::FromRequestParts;
 
 #[derive(FromRequestParts)]
 struct Extractor {

axum-macros/tests/from_request/pass/named_via.rs

@@ -7,7 +7,6 @@ use axum::{
     },
     headers::{self, UserAgent},
 };
-use axum_macros::FromRequest;
 
 #[derive(FromRequest)]
 struct Extractor {

axum-macros/tests/from_request/pass/named_via_parts.rs

@@ -6,7 +6,6 @@ use axum::{
     },
     headers::{self, UserAgent},
 };
-use axum_macros::FromRequestParts;
 
 #[derive(FromRequestParts)]
 struct Extractor {

axum-macros/tests/from_request/pass/override_rejection.rs

@@ -6,7 +6,6 @@ use axum::{
     routing::get,
     Extension, Router,
 };
-use axum_macros::FromRequest;
 
 fn main() {
     let _: Router = Router::new().route("/", get(handler).post(handler_result));

axum-macros/tests/from_request/pass/override_rejection_parts.rs

@@ -6,7 +6,6 @@ use axum::{
     routing::get,
     Extension, Router,
 };
-use axum_macros::FromRequestParts;
 
 fn main() {
     let _: Router = Router::new().route("/", get(handler).post(handler_result));

axum-macros/tests/from_request/pass/state_enum_via.rs

@@ -6,9 +6,10 @@ use axum::{
 use axum_macros::FromRequest;
 
 fn main() {
-    let _: Router<AppState> = Router::with_state(AppState::default())
+    let _: axum::routing::RouterService = Router::new()
         .route("/a", get(|_: AppState| async {}))
-        .route("/b", get(|_: InnerState| async {}));
+        .route("/b", get(|_: InnerState| async {}))
+        .with_state(AppState::default());
 }
 
 #[derive(Clone, FromRequest)]

axum-macros/tests/from_request/pass/state_enum_via_parts.rs

@@ -6,10 +6,11 @@ use axum::{
 use axum_macros::FromRequestParts;
 
 fn main() {
-    let _: Router<AppState> = Router::with_state(AppState::default())
+    let _: axum::routing::RouterService = Router::new()
         .route("/a", get(|_: AppState| async {}))
         .route("/b", get(|_: InnerState| async {}))
-        .route("/c", get(|_: AppState, _: InnerState| async {}));
+        .route("/c", get(|_: AppState, _: InnerState| async {}))
+        .with_state(AppState::default());
 }
 
 #[derive(Clone, FromRequestParts)]

axum-macros/tests/from_request/pass/state_explicit.rs

@@ -6,8 +6,9 @@ use axum::{
 };
 
 fn main() {
-    let _: Router<AppState> = Router::with_state(AppState::default())
-        .route("/b", get(|_: Extractor| async {}));
+    let _: axum::routing::RouterService = Router::new()
+        .route("/b", get(|_: Extractor| async {}))
+        .with_state(AppState::default());
 }
 
 #[derive(FromRequest)]

axum-macros/tests/from_request/pass/state_explicit_parts.rs

@@ -7,8 +7,9 @@ use axum::{
 use std::collections::HashMap;
 
 fn main() {
-    let _: Router<AppState> = Router::with_state(AppState::default())
-        .route("/b", get(|_: Extractor| async {}));
+    let _: axum::routing::RouterService = Router::new()
+        .route("/b", get(|_: Extractor| async {}))
+        .with_state(AppState::default());
 }
 
 #[derive(FromRequestParts)]

axum-macros/tests/from_request/pass/state_field_explicit.rs

@@ -6,8 +6,9 @@ use axum::{
 use axum_macros::FromRequest;
 
 fn main() {
-    let _: Router<AppState> = Router::with_state(AppState::default())
-        .route("/", get(|_: Extractor| async {}));
+    let _: axum::routing::RouterService = Router::new()
+        .route("/", get(|_: Extractor| async {}))
+        .with_state(AppState::default());
 }
 
 #[derive(FromRequest)]

axum-macros/tests/from_request/pass/state_field_infer.rs

@@ -6,8 +6,9 @@ use axum::{
 use axum_macros::FromRequest;
 
 fn main() {
-    let _: Router<AppState> = Router::with_state(AppState::default())
-        .route("/", get(|_: Extractor| async {}));
+    let _: axum::routing::RouterService = Router::new()
+        .route("/", get(|_: Extractor| async {}))
+        .with_state(AppState::default());
 }
 
 #[derive(FromRequest)]

axum-macros/tests/from_request/pass/state_via.rs

@@ -6,9 +6,10 @@ use axum::{
 use axum_macros::FromRequest;
 
 fn main() {
-    let _: Router<AppState> = Router::with_state(AppState::default())
+    let _: axum::routing::RouterService = Router::new()
         .route("/b", get(|_: (), _: AppState| async {}))
-        .route("/c", get(|_: (), _: InnerState| async {}));
+        .route("/c", get(|_: (), _: InnerState| async {}))
+        .with_state(AppState::default());
 }
 
 #[derive(Clone, Default, FromRequest)]

axum-macros/tests/from_request/pass/state_via_infer.rs

@@ -6,8 +6,9 @@ use axum::{
 use axum_macros::FromRequest;
 
 fn main() {
-    let _: Router<AppState> = Router::with_state(AppState::default())
-        .route("/b", get(|_: AppState| async {}));
+    let _: axum::routing::RouterService = Router::new()
+        .route("/b", get(|_: AppState| async {}))
+        .with_state(AppState::default());
 }
 
 // if we're extract "via" `State<AppState>` and not specifying state

axum-macros/tests/from_request/pass/state_via_parts.rs

@@ -6,10 +6,11 @@ use axum::{
 use axum_macros::FromRequestParts;
 
 fn main() {
-    let _: Router<AppState> = Router::with_state(AppState::default())
+    let _: axum::routing::RouterService = Router::new()
         .route("/a", get(|_: AppState, _: InnerState, _: String| async {}))
         .route("/b", get(|_: AppState, _: String| async {}))
-        .route("/c", get(|_: InnerState, _: String| async {}));
+        .route("/c", get(|_: InnerState, _: String| async {}))
+        .with_state(AppState::default());
 }
 
 #[derive(Clone, Default, FromRequestParts)]

axum-macros/tests/from_request/pass/state_with_rejection.rs

@@ -8,8 +8,9 @@ use axum::{
 use axum_macros::FromRequest;
 
 fn main() {
-    let _: Router<AppState> =
-        Router::with_state(AppState::default()).route("/a", get(|_: Extractor| async {}));
+    let _: axum::routing::RouterService = Router::new()
+        .route("/a", get(|_: Extractor| async {}))
+        .with_state(AppState::default());
 }
 
 #[derive(Clone, Default, FromRequest)]