From 02f9ebaee914fa514d97342e641baaf3bfe679e8 Mon Sep 17 00:00:00 2001
From: David Pedersen <david.pdrsn@gmail.com>
Date: Sun, 3 Jul 2022 21:07:29 +0200
Subject: [PATCH] checkpoint

---
 Cargo.toml                                    |  4 +-
 axum-extra/src/extract/cached.rs              | 14 ++--
 axum-extra/src/extract/cookie/mod.rs          | 19 +++--
 axum-extra/src/extract/cookie/private.rs      |  7 +-
 axum-extra/src/extract/cookie/signed.rs       |  7 +-
 axum-extra/src/extract/form.rs                | 17 ++---
 axum-extra/src/extract/query.rs               | 15 ++--
 axum-extra/src/json_lines.rs                  | 61 +++++++--------
 axum-extra/src/routing/mod.rs                 | 76 ++++++++++++-------
 axum-extra/src/routing/resource.rs            | 67 +++++++---------
 axum-extra/src/routing/spa.rs                 | 29 +++----
 axum/src/routing/method_routing.rs            |  7 ++
 .../src/main.rs                               | 10 +--
 13 files changed, 172 insertions(+), 161 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index a84f6fdd..a221fbc5 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,8 +2,8 @@
 members = [
     "axum",
     "axum-core",
-    # "axum-extra",
-    # "axum-macros",
+    "axum-extra",
+    "axum-macros",
 
     # internal crate used to bump the minimum versions we
     # get for some dependencies which otherwise wouldn't build
diff --git a/axum-extra/src/extract/cached.rs b/axum-extra/src/extract/cached.rs
index 0ada78a8..e526aa9c 100644
--- a/axum-extra/src/extract/cached.rs
+++ b/axum-extra/src/extract/cached.rs
@@ -88,14 +88,15 @@ pub struct Cached<T>(pub T);
 struct CachedEntry<T>(T);
 
 #[async_trait]
-impl<B, T> FromRequest<B> for Cached<T>
+impl<S, B, T> FromRequest<S, B> for Cached<T>
 where
+    S: Send,
     B: Send,
-    T: FromRequest<B> + Clone + Send + Sync + 'static,
+    T: FromRequest<S, B> + Clone + Send + Sync + 'static,
 {
     type Rejection = T::Rejection;
 
-    async fn from_request(req: &mut RequestParts<B>) -> Result<Self, Self::Rejection> {
+    async fn from_request(req: &mut RequestParts<S, B>) -> Result<Self, Self::Rejection> {
         match Extension::<CachedEntry<T>>::from_request(req).await {
             Ok(Extension(CachedEntry(value))) => Ok(Self(value)),
             Err(_) => {
@@ -139,19 +140,20 @@ mod tests {
         struct Extractor(Instant);
 
         #[async_trait]
-        impl<B> FromRequest<B> for Extractor
+        impl<S, B> FromRequest<S, B> for Extractor
         where
+            S: Send,
             B: Send,
         {
             type Rejection = Infallible;
 
-            async fn from_request(_req: &mut RequestParts<B>) -> Result<Self, Self::Rejection> {
+            async fn from_request(_req: &mut RequestParts<S, B>) -> Result<Self, Self::Rejection> {
                 COUNTER.fetch_add(1, Ordering::SeqCst);
                 Ok(Self(Instant::now()))
             }
         }
 
-        let mut req = RequestParts::new(Request::new(()));
+        let mut req = RequestParts::new((), Request::new(()));
 
         let first = Cached::<Extractor>::from_request(&mut req).await.unwrap().0;
         assert_eq!(COUNTER.load(Ordering::SeqCst), 1);
diff --git a/axum-extra/src/extract/cookie/mod.rs b/axum-extra/src/extract/cookie/mod.rs
index 86a841cb..f1a51d1a 100644
--- a/axum-extra/src/extract/cookie/mod.rs
+++ b/axum-extra/src/extract/cookie/mod.rs
@@ -88,13 +88,14 @@ pub struct CookieJar {
 }
 
 #[async_trait]
-impl<B> FromRequest<B> for CookieJar
+impl<S, B> FromRequest<S, B> for CookieJar
 where
+    S: Send,
     B: Send,
 {
     type Rejection = Infallible;
 
-    async fn from_request(req: &mut RequestParts<B>) -> Result<Self, Self::Rejection> {
+    async fn from_request(req: &mut RequestParts<S, B>) -> Result<Self, Self::Rejection> {
         let mut jar = cookie_lib::CookieJar::new();
         for cookie in cookies_from_request(req) {
             jar.add_original(cookie);
@@ -103,8 +104,8 @@ where
     }
 }
 
-fn cookies_from_request<B>(
-    req: &mut RequestParts<B>,
+fn cookies_from_request<S, B>(
+    req: &mut RequestParts<S, B>,
 ) -> impl Iterator<Item = Cookie<'static>> + '_ {
     req.headers()
         .get_all(COOKIE)
@@ -226,13 +227,12 @@ mod tests {
                     jar.remove(Cookie::named("key"))
                 }
 
-                let app = Router::<_, Body, _>::new()
+                let app = Router::without_state()
                     .route("/set", get(set_cookie))
                     .route("/get", get(get_cookie))
                     .route("/remove", get(remove_cookie))
                     .layer(Extension(Key::generate()))
-                    .layer(Extension(CustomKey(Key::generate())))
-                    .state(());
+                    .layer(Extension(CustomKey(Key::generate())));
 
                 let res = app
                     .clone()
@@ -295,10 +295,9 @@ mod tests {
             format!("{:?}", jar.get("key"))
         }
 
-        let app = Router::<_, Body, _>::new()
+        let app = Router::without_state()
             .route("/get", get(get_cookie))
-            .layer(Extension(Key::generate()))
-            .state(());
+            .layer(Extension(Key::generate()));
 
         let res = app
             .clone()
diff --git a/axum-extra/src/extract/cookie/private.rs b/axum-extra/src/extract/cookie/private.rs
index a583a3c9..57adb74e 100644
--- a/axum-extra/src/extract/cookie/private.rs
+++ b/axum-extra/src/extract/cookie/private.rs
@@ -74,14 +74,15 @@ impl<K> fmt::Debug for PrivateCookieJar<K> {
 }
 
 #[async_trait]
-impl<B, K> FromRequest<B> for PrivateCookieJar<K>
+impl<S, B, K> FromRequest<S, B> for PrivateCookieJar<K>
 where
     B: Send,
+    S: Send,
     K: Into<Key> + Clone + Send + Sync + 'static,
 {
-    type Rejection = <axum::Extension<K> as FromRequest<B>>::Rejection;
+    type Rejection = <axum::Extension<K> as FromRequest<S, B>>::Rejection;
 
-    async fn from_request(req: &mut RequestParts<B>) -> Result<Self, Self::Rejection> {
+    async fn from_request(req: &mut RequestParts<S, B>) -> Result<Self, Self::Rejection> {
         let key = Extension::<K>::from_request(req).await?.0.into();
 
         let mut jar = cookie_lib::CookieJar::new();
diff --git a/axum-extra/src/extract/cookie/signed.rs b/axum-extra/src/extract/cookie/signed.rs
index 51fb865c..cab8d6af 100644
--- a/axum-extra/src/extract/cookie/signed.rs
+++ b/axum-extra/src/extract/cookie/signed.rs
@@ -92,14 +92,15 @@ impl<K> fmt::Debug for SignedCookieJar<K> {
 }
 
 #[async_trait]
-impl<B, K> FromRequest<B> for SignedCookieJar<K>
+impl<S, B, K> FromRequest<S, B> for SignedCookieJar<K>
 where
     B: Send,
+    S: Send,
     K: Into<Key> + Clone + Send + Sync + 'static,
 {
-    type Rejection = <axum::Extension<K> as FromRequest<B>>::Rejection;
+    type Rejection = <axum::Extension<K> as FromRequest<S, B>>::Rejection;
 
-    async fn from_request(req: &mut RequestParts<B>) -> Result<Self, Self::Rejection> {
+    async fn from_request(req: &mut RequestParts<S, B>) -> Result<Self, Self::Rejection> {
         let key = Extension::<K>::from_request(req).await?.0.into();
 
         let mut jar = cookie_lib::CookieJar::new();
diff --git a/axum-extra/src/extract/form.rs b/axum-extra/src/extract/form.rs
index 238f409f..fdce04ba 100644
--- a/axum-extra/src/extract/form.rs
+++ b/axum-extra/src/extract/form.rs
@@ -54,16 +54,17 @@ impl<T> Deref for Form<T> {
 }
 
 #[async_trait]
-impl<T, B> FromRequest<B> for Form<T>
+impl<T, S, B> FromRequest<S, B> for Form<T>
 where
     T: DeserializeOwned,
     B: HttpBody + Send,
     B::Data: Send,
     B::Error: Into<BoxError>,
+    S: Send,
 {
     type Rejection = FormRejection;
 
-    async fn from_request(req: &mut RequestParts<B>) -> Result<Self, Self::Rejection> {
+    async fn from_request(req: &mut RequestParts<S, B>) -> Result<Self, Self::Rejection> {
         if req.method() == Method::GET {
             let query = req.uri().query().unwrap_or_default();
             let value = serde_html_form::from_str(query)
@@ -84,7 +85,7 @@ where
 }
 
 // this is duplicated in `axum/src/extract/mod.rs`
-fn has_content_type<B>(req: &RequestParts<B>, expected_content_type: &mime::Mime) -> bool {
+fn has_content_type<S, B>(req: &RequestParts<S, B>, expected_content_type: &mime::Mime) -> bool {
     let content_type = if let Some(content_type) = req.headers().get(header::CONTENT_TYPE) {
         content_type
     } else {
@@ -116,12 +117,10 @@ mod tests {
             values: Vec<String>,
         }
 
-        let app = Router::new()
-            .route(
-                "/",
-                post(|Form(data): Form<Data>| async move { data.values.join(",") }),
-            )
-            .state(());
+        let app = Router::without_state().route(
+            "/",
+            post(|Form(data): Form<Data>| async move { data.values.join(",") }),
+        );
 
         let client = TestClient::new(app);
 
diff --git a/axum-extra/src/extract/query.rs b/axum-extra/src/extract/query.rs
index 8638e8ad..38522fa8 100644
--- a/axum-extra/src/extract/query.rs
+++ b/axum-extra/src/extract/query.rs
@@ -58,14 +58,15 @@ use std::ops::Deref;
 pub struct Query<T>(pub T);
 
 #[async_trait]
-impl<T, B> FromRequest<B> for Query<T>
+impl<T, S, B> FromRequest<S, B> for Query<T>
 where
     T: DeserializeOwned,
     B: Send,
+    S: Send,
 {
     type Rejection = QueryRejection;
 
-    async fn from_request(req: &mut RequestParts<B>) -> Result<Self, Self::Rejection> {
+    async fn from_request(req: &mut RequestParts<S, B>) -> Result<Self, Self::Rejection> {
         let query = req.uri().query().unwrap_or_default();
         let value = serde_html_form::from_str(query)
             .map_err(FailedToDeserializeQueryString::__private_new::<T, _>)?;
@@ -97,12 +98,10 @@ mod tests {
             values: Vec<String>,
         }
 
-        let app = Router::new()
-            .route(
-                "/",
-                post(|Query(data): Query<Data>| async move { data.values.join(",") }),
-            )
-            .state(());
+        let app = Router::without_state().route(
+            "/",
+            post(|Query(data): Query<Data>| async move { data.values.join(",") }),
+        );
 
         let client = TestClient::new(app);
 
diff --git a/axum-extra/src/json_lines.rs b/axum-extra/src/json_lines.rs
index f704f581..e16b6695 100644
--- a/axum-extra/src/json_lines.rs
+++ b/axum-extra/src/json_lines.rs
@@ -98,16 +98,17 @@ impl<S> JsonLines<S, AsResponse> {
 }
 
 #[async_trait]
-impl<B, T> FromRequest<B> for JsonLines<T, AsExtractor>
+impl<S, B, T> FromRequest<S, B> for JsonLines<T, AsExtractor>
 where
     B: HttpBody + Send + 'static,
     B::Data: Into<Bytes>,
     B::Error: Into<BoxError>,
     T: DeserializeOwned,
+    S: Send,
 {
     type Rejection = BodyAlreadyExtracted;
 
-    async fn from_request(req: &mut RequestParts<B>) -> Result<Self, Self::Rejection> {
+    async fn from_request(req: &mut RequestParts<S, B>) -> Result<Self, Self::Rejection> {
         // `Stream::lines` isn't a thing so we have to convert it into an `AsyncRead`
         // so we can call `AsyncRead::lines` and then convert it back to a `Stream`
 
@@ -217,24 +218,22 @@ mod tests {
 
     #[tokio::test]
     async fn extractor() {
-        let app = Router::new()
-            .route(
-                "/",
-                post(|mut stream: JsonLines<User>| async move {
-                    assert_eq!(stream.next().await.unwrap().unwrap(), User { id: 1 });
-                    assert_eq!(stream.next().await.unwrap().unwrap(), User { id: 2 });
-                    assert_eq!(stream.next().await.unwrap().unwrap(), User { id: 3 });
+        let app = Router::without_state().route(
+            "/",
+            post(|mut stream: JsonLines<User>| async move {
+                assert_eq!(stream.next().await.unwrap().unwrap(), User { id: 1 });
+                assert_eq!(stream.next().await.unwrap().unwrap(), User { id: 2 });
+                assert_eq!(stream.next().await.unwrap().unwrap(), User { id: 3 });
 
-                    // sources are downcastable to `serde_json::Error`
-                    let err = stream.next().await.unwrap().unwrap_err();
-                    let _: &serde_json::Error = err
-                        .source()
-                        .unwrap()
-                        .downcast_ref::<serde_json::Error>()
-                        .unwrap();
-                }),
-            )
-            .state(());
+                // sources are downcastable to `serde_json::Error`
+                let err = stream.next().await.unwrap().unwrap_err();
+                let _: &serde_json::Error = err
+                    .source()
+                    .unwrap()
+                    .downcast_ref::<serde_json::Error>()
+                    .unwrap();
+            }),
+        );
 
         let client = TestClient::new(app);
 
@@ -257,19 +256,17 @@ mod tests {
 
     #[tokio::test]
     async fn response() {
-        let app = Router::new()
-            .route(
-                "/",
-                get(|| async {
-                    let values = futures_util::stream::iter(vec![
-                        Ok::<_, Infallible>(User { id: 1 }),
-                        Ok::<_, Infallible>(User { id: 2 }),
-                        Ok::<_, Infallible>(User { id: 3 }),
-                    ]);
-                    JsonLines::new(values)
-                }),
-            )
-            .state(());
+        let app = Router::without_state().route(
+            "/",
+            get(|| async {
+                let values = futures_util::stream::iter(vec![
+                    Ok::<_, Infallible>(User { id: 1 }),
+                    Ok::<_, Infallible>(User { id: 2 }),
+                    Ok::<_, Infallible>(User { id: 3 }),
+                ]);
+                JsonLines::new(values)
+            }),
+        );
 
         let client = TestClient::new(app);
 
diff --git a/axum-extra/src/routing/mod.rs b/axum-extra/src/routing/mod.rs
index e78f3276..fbbcab99 100644
--- a/axum-extra/src/routing/mod.rs
+++ b/axum-extra/src/routing/mod.rs
@@ -4,6 +4,7 @@ use axum::{
     handler::Handler,
     http::Request,
     response::{Redirect, Response},
+    routing::{MethodRouter, MissingState},
     Router,
 };
 use std::{convert::Infallible, future::ready};
@@ -29,7 +30,7 @@ pub use self::typed::{FirstElementIs, TypedPath};
 pub use self::spa::SpaRouter;
 
 /// Extension trait that adds additional methods to [`Router`].
-pub trait RouterExt<S, B, R>: sealed::Sealed {
+pub trait RouterExt<S, R, B>: sealed::Sealed {
     /// Add a typed `GET` route to the router.
     ///
     /// The path will be inferred from the first argument to the handler function which must
@@ -39,7 +40,7 @@ pub trait RouterExt<S, B, R>: sealed::Sealed {
     #[cfg(feature = "typed-routing")]
     fn typed_get<H, T, P>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: FirstElementIs<P> + 'static,
         P: TypedPath;
 
@@ -52,7 +53,7 @@ pub trait RouterExt<S, B, R>: sealed::Sealed {
     #[cfg(feature = "typed-routing")]
     fn typed_delete<H, T, P>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: FirstElementIs<P> + 'static,
         P: TypedPath;
 
@@ -65,7 +66,7 @@ pub trait RouterExt<S, B, R>: sealed::Sealed {
     #[cfg(feature = "typed-routing")]
     fn typed_head<H, T, P>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: FirstElementIs<P> + 'static,
         P: TypedPath;
 
@@ -78,7 +79,7 @@ pub trait RouterExt<S, B, R>: sealed::Sealed {
     #[cfg(feature = "typed-routing")]
     fn typed_options<H, T, P>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: FirstElementIs<P> + 'static,
         P: TypedPath;
 
@@ -91,7 +92,7 @@ pub trait RouterExt<S, B, R>: sealed::Sealed {
     #[cfg(feature = "typed-routing")]
     fn typed_patch<H, T, P>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: FirstElementIs<P> + 'static,
         P: TypedPath;
 
@@ -104,7 +105,7 @@ pub trait RouterExt<S, B, R>: sealed::Sealed {
     #[cfg(feature = "typed-routing")]
     fn typed_post<H, T, P>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: FirstElementIs<P> + 'static,
         P: TypedPath;
 
@@ -117,7 +118,7 @@ pub trait RouterExt<S, B, R>: sealed::Sealed {
     #[cfg(feature = "typed-routing")]
     fn typed_put<H, T, P>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: FirstElementIs<P> + 'static,
         P: TypedPath;
 
@@ -130,10 +131,18 @@ pub trait RouterExt<S, B, R>: sealed::Sealed {
     #[cfg(feature = "typed-routing")]
     fn typed_trace<H, T, P>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: FirstElementIs<P> + 'static,
         P: TypedPath;
 
+    fn route_with_tsr(
+        self,
+        path: &str,
+        // TODO(david): constrain this so it only accepts methods
+        // routers containing handlers
+        method_router: MethodRouter<S, MissingState, B, Infallible>,
+    ) -> Self;
+
     /// Add another route to the router with an additional "trailing slash redirect" route.
     ///
     /// If you add a route _without_ a trailing slash, such as `/foo`, this method will also add a
@@ -159,23 +168,23 @@ pub trait RouterExt<S, B, R>: sealed::Sealed {
     ///     .route_with_tsr("/bar/", get(|| async {}));
     /// # let _: Router = app;
     /// ```
-    fn route_with_tsr<T>(self, path: &str, service: T) -> Self
+    fn route_service_with_tsr<T>(self, path: &str, service: T) -> Self
     where
         T: Service<Request<B>, Response = Response, Error = Infallible> + Clone + Send + 'static,
         T::Future: Send + 'static,
         Self: Sized;
 }
 
-impl<S, B, R> RouterExt<S, B, R> for Router<S, B, R>
+impl<S, B, R> RouterExt<S, R, B> for Router<S, R, B>
 where
     B: axum::body::HttpBody + Send + 'static,
+    S: Clone + Send + Sync + 'static,
     R: 'static,
-    S: 'static,
 {
     #[cfg(feature = "typed-routing")]
     fn typed_get<H, T, P>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: FirstElementIs<P> + 'static,
         P: TypedPath,
     {
@@ -185,7 +194,7 @@ where
     #[cfg(feature = "typed-routing")]
     fn typed_delete<H, T, P>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: FirstElementIs<P> + 'static,
         P: TypedPath,
     {
@@ -195,7 +204,7 @@ where
     #[cfg(feature = "typed-routing")]
     fn typed_head<H, T, P>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: FirstElementIs<P> + 'static,
         P: TypedPath,
     {
@@ -205,7 +214,7 @@ where
     #[cfg(feature = "typed-routing")]
     fn typed_options<H, T, P>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: FirstElementIs<P> + 'static,
         P: TypedPath,
     {
@@ -215,7 +224,7 @@ where
     #[cfg(feature = "typed-routing")]
     fn typed_patch<H, T, P>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: FirstElementIs<P> + 'static,
         P: TypedPath,
     {
@@ -225,7 +234,7 @@ where
     #[cfg(feature = "typed-routing")]
     fn typed_post<H, T, P>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: FirstElementIs<P> + 'static,
         P: TypedPath,
     {
@@ -235,7 +244,7 @@ where
     #[cfg(feature = "typed-routing")]
     fn typed_put<H, T, P>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: FirstElementIs<P> + 'static,
         P: TypedPath,
     {
@@ -245,32 +254,42 @@ where
     #[cfg(feature = "typed-routing")]
     fn typed_trace<H, T, P>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: FirstElementIs<P> + 'static,
         P: TypedPath,
     {
         self.route(P::PATH, axum::routing::trace(handler))
     }
 
-    fn route_with_tsr<T>(mut self, path: &str, service: T) -> Self
+    fn route_with_tsr(
+        mut self,
+        path: &str,
+        // TODO(david): constrain this so it only accepts methods
+        // routers containing handlers
+        method_router: MethodRouter<S, MissingState, B, Infallible>,
+    ) -> Self {
+        todo!()
+    }
+
+    fn route_service_with_tsr<T>(mut self, path: &str, service: T) -> Self
     where
         T: Service<Request<B>, Response = Response, Error = Infallible> + Clone + Send + 'static,
         T::Future: Send + 'static,
         Self: Sized,
     {
-        self = self.route(path, service);
+        self = self.route_service(path, service);
 
         let redirect = Redirect::permanent(path);
 
         if let Some(path_without_trailing_slash) = path.strip_suffix('/') {
-            self.route(
+            self.route_service(
                 path_without_trailing_slash,
-                (move || ready(redirect.clone())).into_service(),
+                (move || ready(redirect.clone())).into_service(()),
             )
         } else {
-            self.route(
+            self.route_service(
                 &format!("{}/", path),
-                (move || ready(redirect.clone())).into_service(),
+                (move || ready(redirect.clone())).into_service(()),
             )
         }
     }
@@ -289,10 +308,9 @@ mod tests {
 
     #[tokio::test]
     async fn test_tsr() {
-        let app = Router::new()
+        let app = Router::without_state()
             .route_with_tsr("/foo", get(|| async {}))
-            .route_with_tsr("/bar/", get(|| async {}))
-            .state(());
+            .route_with_tsr("/bar/", get(|| async {}));
 
         let client = TestClient::new(app);
 
diff --git a/axum-extra/src/routing/resource.rs b/axum-extra/src/routing/resource.rs
index d67baa71..2d6d8eba 100644
--- a/axum-extra/src/routing/resource.rs
+++ b/axum-extra/src/routing/resource.rs
@@ -3,7 +3,7 @@ use axum::{
     handler::Handler,
     http::Request,
     response::Response,
-    routing::{delete, get, on, post, MethodFilter, MissingState, WithState},
+    routing::{delete, get, on, post, MethodFilter, MethodRouter, MissingState, WithState},
     Router,
 };
 use std::{convert::Infallible, fmt};
@@ -47,12 +47,12 @@ use tower_service::Service;
 /// let app = Router::new().merge(users);
 /// # let _: Router<axum::body::Body> = app;
 /// ```
-pub struct Resource<S, B = Body, R = MissingState> {
+pub struct Resource<S, R, B> {
     pub(crate) name: String,
-    pub(crate) router: Router<S, B, R>,
+    pub(crate) router: Router<S, R, B>,
 }
 
-impl<S, B, R> fmt::Debug for Resource<S, B, R>
+impl<S, B, R> fmt::Debug for Resource<S, R, B>
 where
     S: fmt::Debug,
 {
@@ -64,7 +64,7 @@ where
     }
 }
 
-impl<S, B> Resource<S, B, MissingState>
+impl<S, B> Resource<S, MissingState, B>
 where
     B: axum::body::HttpBody + Send + 'static,
 {
@@ -77,29 +77,18 @@ where
             router: Default::default(),
         }
     }
-
-    /// TODO(david): docs
-    pub fn state(self, state: S) -> Resource<S, B, WithState>
-    where
-        S: Clone,
-    {
-        Resource {
-            name: self.name,
-            router: self.router.state(state),
-        }
-    }
 }
 
-impl<S, B, R> Resource<S, B, R>
+impl<S, R, B> Resource<S, R, B>
 where
     B: axum::body::HttpBody + Send + 'static,
-    S: 'static,
+    S: Clone + Send + Sync + 'static,
     R: 'static,
 {
     /// Add a handler at `GET /{resource_name}`.
     pub fn index<H, T>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: 'static,
     {
         let path = self.index_create_path();
@@ -109,7 +98,7 @@ where
     /// Add a handler at `POST /{resource_name}`.
     pub fn create<H, T>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: 'static,
     {
         let path = self.index_create_path();
@@ -119,7 +108,7 @@ where
     /// Add a handler at `GET /{resource_name}/new`.
     pub fn new<H, T>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: 'static,
     {
         let path = format!("/{}/new", self.name);
@@ -129,7 +118,7 @@ where
     /// Add a handler at `GET /{resource_name}/:{resource_name}_id`.
     pub fn show<H, T>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: 'static,
     {
         let path = self.show_update_destroy_path();
@@ -139,7 +128,7 @@ where
     /// Add a handler at `GET /{resource_name}/:{resource_name}_id/edit`.
     pub fn edit<H, T>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: 'static,
     {
         let path = format!("/{0}/:{0}_id/edit", self.name);
@@ -149,7 +138,7 @@ where
     /// Add a handler at `PUT or PATCH /resource_name/:{resource_name}_id`.
     pub fn update<H, T>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: 'static,
     {
         let path = self.show_update_destroy_path();
@@ -159,7 +148,7 @@ where
     /// Add a handler at `DELETE /{resource_name}/:{resource_name}_id`.
     pub fn destroy<H, T>(self, handler: H) -> Self
     where
-        H: Handler<T, B>,
+        H: Handler<S, T, B>,
         T: 'static,
     {
         let path = self.show_update_destroy_path();
@@ -169,7 +158,7 @@ where
     /// Nest another router at the "member level".
     ///
     /// The routes will be nested at `/{resource_name}/:{resource_name}_id`.
-    pub fn nest(mut self, router: Router<S, B, MissingState>) -> Self {
+    pub fn nest(mut self, router: Router<S, MissingState, B>) -> Self {
         let path = self.show_update_destroy_path();
         self.router = self.router.nest(&path, router);
         self
@@ -178,7 +167,7 @@ where
     /// Nest another router at the "collection level".
     ///
     /// The routes will be nested at `/{resource_name}`.
-    pub fn nest_collection(mut self, router: Router<S, B, MissingState>) -> Self {
+    pub fn nest_collection(mut self, router: Router<S, MissingState, B>) -> Self {
         let path = self.index_create_path();
         self.router = self.router.nest(&path, router);
         self
@@ -192,18 +181,18 @@ where
         format!("/{0}/:{0}_id", self.name)
     }
 
-    fn route<T>(mut self, path: &str, svc: T) -> Self
-    where
-        T: Service<Request<B>, Response = Response, Error = Infallible> + Clone + Send + 'static,
-        T::Future: Send + 'static,
-    {
-        self.router = self.router.route(path, svc);
+    fn route(
+        mut self,
+        path: &str,
+        method_router: MethodRouter<S, MissingState, B, Infallible>,
+    ) -> Self {
+        self.router = self.router.route(path, method_router);
         self
     }
 }
 
-impl<S, B> From<Resource<S, B, MissingState>> for Router<S, B, MissingState> {
-    fn from(resource: Resource<S, B, MissingState>) -> Self {
+impl<S, B> From<Resource<S, MissingState, B>> for Router<S, MissingState, B> {
+    fn from(resource: Resource<S, MissingState, B>) -> Self {
         resource.router
     }
 }
@@ -233,7 +222,7 @@ mod tests {
                 Router::new().route("/featured", get(|| async move { "users#featured" })),
             );
 
-        let mut app = Router::new().merge(users).state(());
+        let mut app = Router::without_state().merge(users);
 
         assert_eq!(
             call_route(&mut app, Method::GET, "/users").await,
@@ -286,11 +275,7 @@ mod tests {
         );
     }
 
-    async fn call_route(
-        app: &mut Router<(), Body, axum::routing::WithState>,
-        method: Method,
-        uri: &str,
-    ) -> String {
+    async fn call_route(app: &mut Router<(), WithState>, method: Method, uri: &str) -> String {
         let res = app
             .ready()
             .await
diff --git a/axum-extra/src/routing/spa.rs b/axum-extra/src/routing/spa.rs
index 68a50c5c..2e4a4158 100644
--- a/axum-extra/src/routing/spa.rs
+++ b/axum-extra/src/routing/spa.rs
@@ -147,7 +147,7 @@ impl<B, T, F> SpaRouter<B, T, F> {
     }
 }
 
-impl<B, F, T, S> From<SpaRouter<B, T, F>> for Router<S, B, MissingState>
+impl<B, F, T, S> From<SpaRouter<B, T, F>> for Router<S, MissingState, B>
 where
     F: Clone + Send + 'static,
     HandleError<Route<B, io::Error>, F, T>:
@@ -155,17 +155,22 @@ where
     <HandleError<Route<B, io::Error>, F, T> as Service<Request<B>>>::Future: Send,
     B: HttpBody + Send + 'static,
     T: 'static,
-    S: 'static,
+    S: Clone + Send + Sync + 'static,
 {
     fn from(spa: SpaRouter<B, T, F>) -> Self {
         let assets_service = get_service(ServeDir::new(&spa.paths.assets_dir))
-            .handle_error(spa.handle_error.clone());
+            .handle_error(spa.handle_error.clone())
+            // TODO(david): having to do this is annoying
+            .state(());
+
+        let fallback_service = get_service(ServeFile::new(&spa.paths.index_file))
+            .handle_error(spa.handle_error)
+            // TODO(david): having to do this is annoying
+            .state(());
 
         Router::new()
             .nest_service(&spa.paths.assets_path, assets_service)
-            .fallback(
-                get_service(ServeFile::new(&spa.paths.index_file)).handle_error(spa.handle_error),
-            )
+            .fallback_service(fallback_service)
     }
 }
 
@@ -213,10 +218,9 @@ mod tests {
 
     #[tokio::test]
     async fn basic() {
-        let app = Router::new()
+        let app = Router::without_state()
             .route("/foo", get(|| async { "GET /foo" }))
-            .merge(SpaRouter::new("/assets", "test_files"))
-            .state(());
+            .merge(SpaRouter::new("/assets", "test_files"));
         let client = TestClient::new(app);
 
         let res = client.get("/").send().await;
@@ -241,9 +245,8 @@ mod tests {
 
     #[tokio::test]
     async fn setting_index_file() {
-        let app = Router::new()
-            .merge(SpaRouter::new("/assets", "test_files").index_file("index_2.html"))
-            .state(());
+        let app = Router::without_state()
+            .merge(SpaRouter::new("/assets", "test_files").index_file("index_2.html"));
         let client = TestClient::new(app);
 
         let res = client.get("/").send().await;
@@ -267,6 +270,6 @@ mod tests {
 
         let spa = SpaRouter::new("/assets", "test_files").handle_error(handle_error);
 
-        Router::<(), Body, _>::new().merge(spa);
+        Router::<()>::new().merge(spa);
     }
 }
diff --git a/axum/src/routing/method_routing.rs b/axum/src/routing/method_routing.rs
index 5a93c420..9b46e308 100644
--- a/axum/src/routing/method_routing.rs
+++ b/axum/src/routing/method_routing.rs
@@ -1469,4 +1469,11 @@ mod tests {
     async fn created() -> (StatusCode, &'static str) {
         (StatusCode::CREATED, "created")
     }
+
+    #[test]
+    fn service_constructors_have_state() {
+        // shouldn't have to do
+        // get_service(...).state(...)
+        todo!()
+    }
 }
diff --git a/examples/routes-and-handlers-close-together/src/main.rs b/examples/routes-and-handlers-close-together/src/main.rs
index 5e52ad7b..2e6510d0 100644
--- a/examples/routes-and-handlers-close-together/src/main.rs
+++ b/examples/routes-and-handlers-close-together/src/main.rs
@@ -12,7 +12,7 @@ use std::net::SocketAddr;
 
 #[tokio::main]
 async fn main() {
-    let app = Router::new()
+    let app = Router::without_state()
         .merge(root())
         .merge(get_foo())
         .merge(post_foo());
@@ -25,7 +25,7 @@ async fn main() {
         .unwrap();
 }
 
-fn root() -> Router {
+fn root() -> Router<()> {
     async fn handler() -> &'static str {
         "Hello, World!"
     }
@@ -33,7 +33,7 @@ fn root() -> Router {
     route("/", get(handler))
 }
 
-fn get_foo() -> Router {
+fn get_foo() -> Router<()> {
     async fn handler() -> &'static str {
         "Hi from `GET /foo`"
     }
@@ -41,7 +41,7 @@ fn get_foo() -> Router {
     route("/foo", get(handler))
 }
 
-fn post_foo() -> Router {
+fn post_foo() -> Router<()> {
     async fn handler() -> &'static str {
         "Hi from `POST /foo`"
     }
@@ -49,6 +49,6 @@ fn post_foo() -> Router {
     route("/foo", post(handler))
 }
 
-fn route(path: &str, method_router: MethodRouter) -> Router {
+fn route(path: &str, method_router: MethodRouter<()>) -> Router<()> {
     Router::new().route(path, method_router)
 }