Layer to application/x-www-form-urlencoded bodies

crates/http/Cargo.toml

@@ -21,6 +21,7 @@ opentelemetry-semantic-conventions = "0.9.0"
 rustls = "0.20.6"
 serde = "1.0.142"
 serde_json = "1.0.83"
+serde_urlencoded = "0.7.1"
 thiserror = "1.0.32"
 tokio = { version = "1.20.1", features = ["sync", "parking_lot"] }
 tower = { version = "0.4.13", features = ["timeout", "limit"] }

crates/http/src/ext.rs

@@ -19,6 +19,7 @@ use tower_http::cors::CorsLayer;
 
 use crate::layers::{
     body_to_bytes::{BodyToBytes, BodyToBytesLayer},
+    form_urlencoded_request::{FormUrlencodedRequest, FormUrlencodedRequestLayer},
     json_request::{JsonRequest, JsonRequestLayer},
     json_response::{JsonResponse, JsonResponseLayer},
 };
@@ -76,6 +77,10 @@ pub trait ServiceExt: Sized {
     fn json_request<T>(self) -> JsonRequest<Self, T> {
         JsonRequest::new(self)
     }
+
+    fn form_urlencoded_request<T>(self) -> FormUrlencodedRequest<Self, T> {
+        FormUrlencodedRequest::new(self)
+    }
 }
 
 impl<S> ServiceExt for S {}
@@ -84,6 +89,7 @@ pub trait ServiceBuilderExt<L>: Sized {
     fn response_to_bytes(self) -> ServiceBuilder<Stack<BodyToBytesLayer, L>>;
     fn json_response<T>(self) -> ServiceBuilder<Stack<JsonResponseLayer<T>, L>>;
     fn json_request<T>(self) -> ServiceBuilder<Stack<JsonRequestLayer<T>, L>>;
+    fn form_urlencoded_request<T>(self) -> ServiceBuilder<Stack<FormUrlencodedRequestLayer<T>, L>>;
 }
 
 impl<L> ServiceBuilderExt<L> for ServiceBuilder<L> {
@@ -98,4 +104,8 @@ impl<L> ServiceBuilderExt<L> for ServiceBuilder<L> {
     fn json_request<T>(self) -> ServiceBuilder<Stack<JsonRequestLayer<T>, L>> {
         self.layer(JsonRequestLayer::default())
     }
+
+    fn form_urlencoded_request<T>(self) -> ServiceBuilder<Stack<FormUrlencodedRequestLayer<T>, L>> {
+        self.layer(FormUrlencodedRequestLayer::default())
+    }
 }

crates/http/src/layers/form_urlencoded_request.rs

@@ -0,0 +1,122 @@
+// Copyright 2022 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::{future::Ready, marker::PhantomData, task::Poll};
+
+use bytes::Bytes;
+use futures_util::{
+    future::{Either, MapErr},
+    FutureExt, TryFutureExt,
+};
+use headers::{ContentType, HeaderMapExt};
+use http::Request;
+use http_body::Full;
+use serde::Serialize;
+use thiserror::Error;
+use tower::{Layer, Service};
+
+#[derive(Debug, Error)]
+pub enum Error<Service> {
+    #[error(transparent)]
+    Service { inner: Service },
+
+    #[error("could not serialize form payload")]
+    Serialize {
+        #[source]
+        inner: serde_urlencoded::ser::Error,
+    },
+}
+
+impl<S> Error<S> {
+    fn service(source: S) -> Self {
+        Self::Service { inner: source }
+    }
+
+    fn serialize(source: serde_urlencoded::ser::Error) -> Self {
+        Self::Serialize { inner: source }
+    }
+}
+
+#[derive(Clone)]
+pub struct FormUrlencodedRequest<S, T> {
+    inner: S,
+    _t: PhantomData<T>,
+}
+
+impl<S, T> FormUrlencodedRequest<S, T> {
+    pub const fn new(inner: S) -> Self {
+        Self {
+            inner,
+            _t: PhantomData,
+        }
+    }
+}
+
+impl<S, T> Service<Request<T>> for FormUrlencodedRequest<S, T>
+where
+    S: Service<Request<Full<Bytes>>>,
+    S::Future: Send + 'static,
+    S::Error: 'static,
+    T: Serialize,
+{
+    type Error = Error<S::Error>;
+    type Response = S::Response;
+    type Future = Either<
+        Ready<Result<Self::Response, Self::Error>>,
+        MapErr<S::Future, fn(S::Error) -> Self::Error>,
+    >;
+
+    fn poll_ready(&mut self, cx: &mut std::task::Context<'_>) -> Poll<Result<(), Self::Error>> {
+        self.inner.poll_ready(cx).map_err(Error::service)
+    }
+
+    fn call(&mut self, request: Request<T>) -> Self::Future {
+        let (mut parts, body) = request.into_parts();
+
+        parts.headers.typed_insert(ContentType::form_url_encoded());
+
+        let body = match serde_urlencoded::to_string(&body) {
+            Ok(body) => Full::new(Bytes::from(body)),
+            Err(err) => return std::future::ready(Err(Error::serialize(err))).left_future(),
+        };
+
+        let request = Request::from_parts(parts, body);
+
+        self.inner
+            .call(request)
+            .map_err(Error::service as fn(S::Error) -> Self::Error)
+            .right_future()
+    }
+}
+
+#[derive(Clone, Copy)]
+pub struct FormUrlencodedRequestLayer<T> {
+    _t: PhantomData<T>,
+}
+
+impl<T> Default for FormUrlencodedRequestLayer<T> {
+    fn default() -> Self {
+        Self {
+            _t: PhantomData::default(),
+        }
+    }
+}
+
+impl<S, T> Layer<S> for FormUrlencodedRequestLayer<T> {
+    type Service = FormUrlencodedRequest<S, T>;
+
+    fn layer(&self, inner: S) -> Self::Service {
+        FormUrlencodedRequest::new(inner)
+    }
+}

crates/http/src/layers/json_request.rs

@@ -19,7 +19,8 @@ use futures_util::{
     future::{Either, MapErr},
     FutureExt, TryFutureExt,
 };
-use http::{header::CONTENT_TYPE, HeaderValue, Request};
+use headers::{ContentType, HeaderMapExt};
+use http::Request;
 use http_body::Full;
 use serde::Serialize;
 use thiserror::Error;
@@ -83,9 +84,7 @@ where
     fn call(&mut self, request: Request<T>) -> Self::Future {
         let (mut parts, body) = request.into_parts();
 
-        parts
-            .headers
-            .insert(CONTENT_TYPE, HeaderValue::from_static("application/json"));
+        parts.headers.typed_insert(ContentType::json());
 
         let body = match serde_json::to_vec(&body) {
             Ok(body) => Full::new(Bytes::from(body)),

crates/http/src/layers/json_response.rs

@@ -27,7 +27,7 @@ pub enum Error<Service> {
     Service { inner: Service },
 
     #[error("could not parse JSON payload")]
-    Json {
+    Serialize {
         #[source]
         inner: serde_json::Error,
     },
@@ -38,8 +38,8 @@ impl<S> Error<S> {
         Self::Service { inner: source }
     }
 
-    fn json(source: serde_json::Error) -> Self {
-        Self::Json { inner: source }
+    fn serialize(source: serde_json::Error) -> Self {
+        Self::Serialize { inner: source }
     }
 }
 
@@ -85,7 +85,7 @@ where
             let response = res.map_err(Error::service)?;
             let (parts, body) = response.into_parts();
 
-            let body = serde_json::from_reader(body.reader()).map_err(Error::json)?;
+            let body = serde_json::from_reader(body.reader()).map_err(Error::serialize)?;
 
             let res = Response::from_parts(parts, body);
             Ok(res)

crates/http/src/layers/mod.rs

@@ -14,6 +14,7 @@
 
 pub(crate) mod body_to_bytes;
 pub(crate) mod client;
+pub(crate) mod form_urlencoded_request;
 pub(crate) mod json_request;
 pub(crate) mod json_response;
 pub mod otel;