diff --git a/axum-extra/CHANGELOG.md b/axum-extra/CHANGELOG.md index 4722a6ac..0e435aa8 100644 --- a/axum-extra/CHANGELOG.md +++ b/axum-extra/CHANGELOG.md @@ -18,6 +18,7 @@ and this project adheres to [Semantic Versioning]. - **added:** Support chaining handlers with `HandlerCallWithExtractors::or` ([#1170]) - **change:** axum-extra's MSRV is now 1.60 ([#1239]) - **added:** Add Protocol Buffer extractor and response ([#1239]) +- **added:** `WithRejection` extractor for customizing other extractors' rejections ([#1262]) - **added:** Add sync constructors to `CookieJar`, `PrivateCookieJar`, and `SignedCookieJar` so they're easier to use in custom middleware @@ -26,6 +27,7 @@ and this project adheres to [Semantic Versioning]. [#1170]: https://github.com/tokio-rs/axum/pull/1170 [#1214]: https://github.com/tokio-rs/axum/pull/1214 [#1239]: https://github.com/tokio-rs/axum/pull/1239 +[#1262]: https://github.com/tokio-rs/axum/pull/1262 # 0.3.5 (27. June, 2022) diff --git a/axum-extra/src/extract/mod.rs b/axum-extra/src/extract/mod.rs index 22e19559..e795cfb7 100644 --- a/axum-extra/src/extract/mod.rs +++ b/axum-extra/src/extract/mod.rs @@ -11,6 +11,8 @@ pub mod cookie; #[cfg(feature = "query")] mod query; +mod with_rejection; + pub use self::cached::Cached; #[cfg(feature = "cookie")] @@ -31,3 +33,5 @@ pub use self::query::Query; #[cfg(feature = "json-lines")] #[doc(no_inline)] pub use crate::json_lines::JsonLines; + +pub use self::with_rejection::WithRejection; diff --git a/axum-extra/src/extract/with_rejection.rs b/axum-extra/src/extract/with_rejection.rs new file mode 100644 index 00000000..e87c3d5e --- /dev/null +++ b/axum-extra/src/extract/with_rejection.rs @@ -0,0 +1,165 @@ +use axum::async_trait; +use axum::extract::{FromRequest, RequestParts}; +use axum::response::IntoResponse; +use std::fmt::Debug; +use std::marker::PhantomData; +use std::ops::{Deref, DerefMut}; + +/// Extractor for customizing extractor rejections +/// +/// `WithRejection` wraps another extractor and gives you the result. If the +/// extraction fails, the `Rejection` is transformed into `R` and returned as a +/// response +/// +/// `E` is expected to implement [`FromRequest`] +/// +/// `R` is expected to implement [`IntoResponse`] and [`From`] +/// +/// +/// # Example +/// +/// ```rust +/// use axum::extract::rejection::JsonRejection; +/// use axum::response::{Response, IntoResponse}; +/// use axum::Json; +/// use axum_extra::extract::WithRejection; +/// use serde::Deserialize; +/// +/// struct MyRejection { /* ... */ } +/// +/// impl From for MyRejection { +/// fn from(rejection: JsonRejection) -> MyRejection { +/// // ... +/// # todo!() +/// } +/// } +/// +/// impl IntoResponse for MyRejection { +/// fn into_response(self) -> Response { +/// // ... +/// # todo!() +/// } +/// } +/// #[derive(Debug, Deserialize)] +/// struct Person { /* ... */ } +/// +/// async fn handler( +/// // If the `Json` extractor ever fails, `MyRejection` will be sent to the +/// // client using the `IntoResponse` impl +/// WithRejection(Json(Person), _): WithRejection, MyRejection> +/// ) { /* ... */ } +/// # let _: axum::Router = axum::Router::new().route("/", axum::routing::get(handler)); +/// ``` +/// +/// [`FromRequest`]: axum::extract::FromRequest +/// [`IntoResponse`]: axum::response::IntoResponse +/// [`From`]: std::convert::From +pub struct WithRejection(pub E, pub PhantomData); + +impl WithRejection { + /// Returns the wrapped extractor + fn into_inner(self) -> E { + self.0 + } +} + +impl Debug for WithRejection +where + E: Debug, +{ + fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { + f.debug_tuple("WithRejection") + .field(&self.0) + .field(&self.1) + .finish() + } +} + +impl Clone for WithRejection +where + E: Clone, +{ + fn clone(&self) -> Self { + Self(self.0.clone(), self.1.clone()) + } +} + +impl Copy for WithRejection where E: Copy {} + +impl Default for WithRejection { + fn default() -> Self { + Self(Default::default(), Default::default()) + } +} + +impl Deref for WithRejection { + type Target = E; + + fn deref(&self) -> &Self::Target { + &self.0 + } +} + +impl DerefMut for WithRejection { + fn deref_mut(&mut self) -> &mut Self::Target { + &mut self.0 + } +} + +#[async_trait] +impl FromRequest for WithRejection +where + B: Send, + E: FromRequest, + R: From + IntoResponse, +{ + type Rejection = R; + + async fn from_request(req: &mut RequestParts) -> Result { + let extractor = req.extract::().await?; + Ok(WithRejection(extractor, PhantomData)) + } +} + +#[cfg(test)] +mod tests { + use axum::http::Request; + use axum::response::Response; + + use super::*; + + #[tokio::test] + async fn extractor_rejection_is_transformed() { + struct TestExtractor; + struct TestRejection; + + #[async_trait] + impl FromRequest for TestExtractor { + type Rejection = (); + + async fn from_request(_: &mut RequestParts) -> Result { + Err(()) + } + } + + impl IntoResponse for TestRejection { + fn into_response(self) -> Response { + ().into_response() + } + } + + impl From<()> for TestRejection { + fn from(_: ()) -> Self { + TestRejection + } + } + + let mut req = RequestParts::new(Request::new(())); + + let result = req + .extract::>() + .await; + + assert!(matches!(result, Err(TestRejection))) + } +} diff --git a/examples/customize-extractor-error/src/main.rs b/examples/customize-extractor-error/src/main.rs index bc0973b4..be5ef595 100644 --- a/examples/customize-extractor-error/src/main.rs +++ b/examples/customize-extractor-error/src/main.rs @@ -3,6 +3,9 @@ //! ```not_rust //! cd examples && cargo run -p example-customize-extractor-error //! ``` +//! +//! See https://docs.rs/axum-extra/0.3.7/axum_extra/extract/struct.WithRejection.html +//! example for creating custom errors from already existing extractors use axum::{ async_trait,