From 1191b58083b1a4684ed5367ca427292de5e102f6 Mon Sep 17 00:00:00 2001
From: Jonas Platte <jplatte+git@posteo.de>
Date: Fri, 1 Apr 2022 09:25:15 +0200
Subject: [PATCH] Add `RequestParts::extract` (#897)

---
 axum-core/CHANGELOG.md       |  2 +-
 axum-core/src/extract/mod.rs | 32 ++++++++++++++++++++++++++++++++
 axum/CHANGELOG.md            |  2 +-
 3 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/axum-core/CHANGELOG.md b/axum-core/CHANGELOG.md
index 68f48050..ecf78f31 100644
--- a/axum-core/CHANGELOG.md
+++ b/axum-core/CHANGELOG.md
@@ -7,7 +7,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 # Unreleased
 
-- None.
+- **added:** Add `RequestParts::extract` which allows applying an extractor as a method call
 
 # 0.2.0 (31. March, 2022)
 
diff --git a/axum-core/src/extract/mod.rs b/axum-core/src/extract/mod.rs
index 680234fe..a1406f50 100644
--- a/axum-core/src/extract/mod.rs
+++ b/axum-core/src/extract/mod.rs
@@ -113,6 +113,38 @@ impl<B> RequestParts<B> {
         }
     }
 
+    /// Apply an extractor to this `RequestParts`.
+    ///
+    /// `req.extract::<Extractor>()` is equivalent to `Extractor::from_request(req)`.
+    /// This function simply exists as a convenience.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # struct MyExtractor {}
+    ///
+    /// use std::convert::Infallible;
+    ///
+    /// use async_trait::async_trait;
+    /// use axum::extract::{FromRequest, RequestParts};
+    /// use http::{Method, Uri};
+    ///
+    /// #[async_trait]
+    /// impl<B: Send> FromRequest<B> for MyExtractor {
+    ///     type Rejection = Infallible;
+    ///
+    ///     async fn from_request(req: &mut RequestParts<B>) -> Result<Self, Infallible> {
+    ///         let method = req.extract::<Method>().await?;
+    ///         let path = req.extract::<Uri>().await?.path().to_owned();
+    ///
+    ///         todo!()
+    ///     }
+    /// }
+    /// ```
+    pub async fn extract<E: FromRequest<B>>(&mut self) -> Result<E, E::Rejection> {
+        E::from_request(self).await
+    }
+
     /// Convert this `RequestParts` back into a [`Request`].
     ///
     /// Fails if The request body has been extracted, that is [`take_body`] has
diff --git a/axum/CHANGELOG.md b/axum/CHANGELOG.md
index 32db74be..8e9bdac1 100644
--- a/axum/CHANGELOG.md
+++ b/axum/CHANGELOG.md
@@ -7,7 +7,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 # Unreleased
 
-- None.
+- **added:** Add `RequestParts::extract` which allows applying an extractor as a method call
 
 # 0.5.0 (31. March, 2022)