Add `RawPathParams` (#1713)

8 files changed, 159 insertions, 6 deletions

diff --git a/axum-macros/tests/debug_handler/fail/argument_not_extractor.stderr b/axum-macros/tests/debug_handler/fail/argument_not_extractor.stderr
index 0afef5f2..360163ca 100644
--- a/axum-macros/tests/debug_handler/fail/argument_not_extractor.stderr
+++ b/axum-macros/tests/debug_handler/fail/argument_not_extractor.stderr
@@ -15,7 +15,7 @@ error[E0277]: the trait bound `bool: FromRequestParts<()>` is not satisfied
             <(T1, T2, T3, T4, T5, T6) as FromRequestParts<S>>
             <(T1, T2, T3, T4, T5, T6, T7) as FromRequestParts<S>>
             <(T1, T2, T3, T4, T5, T6, T7, T8) as FromRequestParts<S>>
-          and 25 others
+          and 26 others
   = note: required for `bool` to implement `FromRequest<(), Body, axum_core::extract::private::ViaParts>`
 note: required by a bound in `__axum_macros_check_handler_0_from_request_check`
  --> tests/debug_handler/fail/argument_not_extractor.rs:4:23
diff --git a/axum-macros/tests/debug_handler/fail/doesnt_implement_from_request_parts.stderr b/axum-macros/tests/debug_handler/fail/doesnt_implement_from_request_parts.stderr
index 9614cf4e..70a9be7a 100644
--- a/axum-macros/tests/debug_handler/fail/doesnt_implement_from_request_parts.stderr
+++ b/axum-macros/tests/debug_handler/fail/doesnt_implement_from_request_parts.stderr
@@ -15,6 +15,6 @@ error[E0277]: the trait bound `String: FromRequestParts<()>` is not satisfied
             <(T1, T2, T3, T4, T5, T6) as FromRequestParts<S>>
             <(T1, T2, T3, T4, T5, T6, T7) as FromRequestParts<S>>
             <(T1, T2, T3, T4, T5, T6, T7, T8) as FromRequestParts<S>>
-          and 25 others
+          and 26 others
   = help: see issue #48214
   = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
diff --git a/axum-macros/tests/debug_handler/fail/wrong_return_type.stderr b/axum-macros/tests/debug_handler/fail/wrong_return_type.stderr
index 74df8fd0..e6a33a62 100644
--- a/axum-macros/tests/debug_handler/fail/wrong_return_type.stderr
+++ b/axum-macros/tests/debug_handler/fail/wrong_return_type.stderr
@@ -13,7 +13,7 @@ error[E0277]: the trait bound `bool: IntoResponse` is not satisfied
             (Response<()>, T1, R)
             (Response<()>, T1, T2, R)
             (Response<()>, T1, T2, T3, R)
-          and 122 others
+          and 124 others
 note: required by a bound in `__axum_macros_check_handler_into_response::{closure#0}::check`
  --> tests/debug_handler/fail/wrong_return_type.rs:4:23
   |
diff --git a/axum-macros/tests/from_request/fail/parts_extracting_body.stderr b/axum-macros/tests/from_request/fail/parts_extracting_body.stderr
index 63062d42..54c0dc02 100644
--- a/axum-macros/tests/from_request/fail/parts_extracting_body.stderr
+++ b/axum-macros/tests/from_request/fail/parts_extracting_body.stderr
@@ -15,4 +15,4 @@ error[E0277]: the trait bound `String: FromRequestParts<S>` is not satisfied
             <(T1, T2, T3, T4, T5, T6) as FromRequestParts<S>>
             <(T1, T2, T3, T4, T5, T6, T7) as FromRequestParts<S>>
             <(T1, T2, T3, T4, T5, T6, T7, T8) as FromRequestParts<S>>
-          and 26 others
+          and 27 others
diff --git a/axum/CHANGELOG.md b/axum/CHANGELOG.md
index d956b3af..f312e3b7 100644
--- a/axum/CHANGELOG.md
+++ b/axum/CHANGELOG.md
@@ -9,12 +9,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - **added:** Implement `IntoResponse` for `&'static [u8; N]` and `[u8; N]` ([#1690])
 - **fixed:** Make `Path` support types uses `serde::Deserializer::deserialize_any` ([#1693])
+- **added:** Add `RawPathParams` ([#1713])
 - **added:** Implement `Clone` and `Service` for `axum::middleware::Next` ([#1712])
 - **fixed:** Document required tokio features to run "Hello, World!" example ([#1715])
 
 [#1690]: https://github.com/tokio-rs/axum/pull/1690
 [#1693]: https://github.com/tokio-rs/axum/pull/1693
 [#1712]: https://github.com/tokio-rs/axum/pull/1712
+[#1713]: https://github.com/tokio-rs/axum/pull/1713
 [#1715]: https://github.com/tokio-rs/axum/pull/1715
 
 # 0.6.2 (9. January, 2023)
diff --git a/axum/src/extract/mod.rs b/axum/src/extract/mod.rs
index ed4e227b..cb4ebcd9 100644
--- a/axum/src/extract/mod.rs
+++ b/axum/src/extract/mod.rs
@@ -26,7 +26,7 @@ pub use axum_macros::{FromRef, FromRequest, FromRequestParts};
 #[allow(deprecated)]
 pub use self::{
     host::Host,
-    path::Path,
+    path::{Path, RawPathParams},
     raw_form::RawForm,
     raw_query::RawQuery,
     request_parts::{BodyStream, RawBody},
diff --git a/axum/src/extract/path/mod.rs b/axum/src/extract/path/mod.rs
index 44c9bc04..088ed068 100644
--- a/axum/src/extract/path/mod.rs
+++ b/axum/src/extract/path/mod.rs
@@ -6,6 +6,7 @@ mod de;
 use crate::{
     extract::{rejection::*, FromRequestParts},
     routing::url_params::UrlParams,
+    util::PercentDecodedStr,
 };
 use async_trait::async_trait;
 use axum_core::response::{IntoResponse, Response};
@@ -14,6 +15,7 @@ use serde::de::DeserializeOwned;
 use std::{
     fmt,
     ops::{Deref, DerefMut},
+    sync::Arc,
 };
 
 /// Extractor that will get captures from the URL and parse them using
@@ -426,6 +428,125 @@ impl fmt::Display for FailedToDeserializePathParams {
 
 impl std::error::Error for FailedToDeserializePathParams {}
 
+/// Extractor that will get captures from the URL without deserializing them.
+///
+/// In general you should prefer to use [`Path`] as it is higher level, however `RawPathParams` is
+/// suitable if just want the raw params without deserializing them and thus saving some
+/// allocations.
+///
+/// Any percent encoded parameters will be automatically decoded. The decoded parameters must be
+/// valid UTF-8, otherwise `RawPathParams` will fail and return a `400 Bad Request` response.
+///
+/// # Example
+///
+/// ```rust,no_run
+/// use axum::{
+///     extract::RawPathParams,
+///     routing::get,
+///     Router,
+/// };
+///
+/// async fn users_teams_show(params: RawPathParams) {
+///     for (key, value) in &params {
+///         println!("{key:?} = {value:?}");
+///     }
+/// }
+///
+/// let app = Router::new().route("/users/:user_id/team/:team_id", get(users_teams_show));
+/// # let _: Router = app;
+/// ```
+#[derive(Debug)]
+pub struct RawPathParams(Vec<(Arc<str>, PercentDecodedStr)>);
+
+#[async_trait]
+impl<S> FromRequestParts<S> for RawPathParams
+where
+    S: Send + Sync,
+{
+    type Rejection = RawPathParamsRejection;
+
+    async fn from_request_parts(parts: &mut Parts, _state: &S) -> Result<Self, Self::Rejection> {
+        let params = match parts.extensions.get::<UrlParams>() {
+            Some(UrlParams::Params(params)) => params,
+            Some(UrlParams::InvalidUtf8InPathParam { key }) => {
+                return Err(InvalidUtf8InPathParam {
+                    key: Arc::clone(key),
+                }
+                .into());
+            }
+            None => {
+                return Err(MissingPathParams.into());
+            }
+        };
+
+        Ok(Self(params.clone()))
+    }
+}
+
+impl RawPathParams {
+    /// Get an iterator over the path parameters.
+    pub fn iter(&self) -> RawPathParamsIter<'_> {
+        self.into_iter()
+    }
+}
+
+impl<'a> IntoIterator for &'a RawPathParams {
+    type Item = (&'a str, &'a str);
+    type IntoIter = RawPathParamsIter<'a>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        RawPathParamsIter(self.0.iter())
+    }
+}
+
+/// An iterator over raw path parameters.
+///
+/// Created with [`RawPathParams::iter`].
+#[derive(Debug)]
+pub struct RawPathParamsIter<'a>(std::slice::Iter<'a, (Arc<str>, PercentDecodedStr)>);
+
+impl<'a> Iterator for RawPathParamsIter<'a> {
+    type Item = (&'a str, &'a str);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let (key, value) = self.0.next()?;
+        Some((&**key, value.as_str()))
+    }
+}
+
+/// Rejection used by [`RawPathParams`] if a parameter contained text that, once percent decoded,
+/// wasn't valid UTF-8.
+#[derive(Debug)]
+pub struct InvalidUtf8InPathParam {
+    key: Arc<str>,
+}
+
+impl InvalidUtf8InPathParam {
+    /// Get the response body text used for this rejection.
+    pub fn body_text(&self) -> String {
+        self.to_string()
+    }
+
+    /// Get the status code used for this rejection.
+    pub fn status(&self) -> StatusCode {
+        StatusCode::BAD_REQUEST
+    }
+}
+
+impl fmt::Display for InvalidUtf8InPathParam {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "Invalid UTF-8 in `{}`", self.key)
+    }
+}
+
+impl std::error::Error for InvalidUtf8InPathParam {}
+
+impl IntoResponse for InvalidUtf8InPathParam {
+    fn into_response(self) -> Response {
+        (self.status(), self.body_text()).into_response()
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -710,4 +831,23 @@ mod tests {
             .await
             .starts_with("Wrong number of path arguments for `Path`. Expected 1 but got 2"));
     }
+
+    #[crate::test]
+    async fn raw_path_params() {
+        let app = Router::new().route(
+            "/:a/:b/:c",
+            get(|params: RawPathParams| async move {
+                params
+                    .into_iter()
+                    .map(|(key, value)| format!("{key}={value}"))
+                    .collect::<Vec<_>>()
+                    .join(" ")
+            }),
+        );
+
+        let client = TestClient::new(app);
+        let res = client.get("/foo/bar/baz").send().await;
+        let body = res.text().await;
+        assert_eq!(body, "a=foo b=bar c=baz");
+    }
 }
diff --git a/axum/src/extract/rejection.rs b/axum/src/extract/rejection.rs
index 0b382936..0bb2df04 100644
--- a/axum/src/extract/rejection.rs
+++ b/axum/src/extract/rejection.rs
@@ -1,6 +1,6 @@
 //! Rejection response types.
 
-pub use crate::extract::path::FailedToDeserializePathParams;
+pub use crate::extract::path::{FailedToDeserializePathParams, InvalidUtf8InPathParam};
 pub use axum_core::extract::rejection::*;
 
 #[cfg(feature = "json")]
@@ -156,6 +156,17 @@ composite_rejection! {
 }
 
 composite_rejection! {
+    /// Rejection used for [`RawPathParams`](super::RawPathParams).
+    ///
+    /// Contains one variant for each way the [`RawPathParams`](super::RawPathParams) extractor
+    /// can fail.
+    pub enum RawPathParamsRejection {
+        InvalidUtf8InPathParam,
+        MissingPathParams,
+    }
+}
+
+composite_rejection! {
     /// Rejection used for [`Host`](super::Host).
     ///
     /// Contains one variant for each way the [`Host`](super::Host) extractor