feat: request, response and response body hooks

src/async_impl/client.rs

@@ -23,6 +23,7 @@ use std::task::{Context, Poll};
 use tokio::time::Sleep;
 
 use super::decoder::Accepts;
+use super::hooks::{RequestHook, ResponseBodyHook, ResponseHook};
 use super::request::{Request, RequestBuilder};
 use super::response::Response;
 use super::Body;
@@ -167,6 +168,9 @@ struct Config {
     quic_send_window: Option<u64>,
     dns_overrides: HashMap<String, Vec<SocketAddr>>,
     dns_resolver: Option<Arc<dyn Resolve>>,
+    request_hook: Option<Arc<dyn RequestHook>>,
+    response_hook: Option<Arc<dyn ResponseHook>>,
+    response_body_hook: Option<Arc<dyn ResponseBodyHook>>,
 }
 
 impl Default for ClientBuilder {
@@ -265,6 +269,9 @@ impl ClientBuilder {
                 #[cfg(feature = "http3")]
                 quic_send_window: None,
                 dns_resolver: None,
+                request_hook: None,
+                response_hook: None,
+                response_body_hook: None,
             },
         }
     }
@@ -777,6 +784,9 @@ impl ClientBuilder {
                 proxies,
                 proxies_maybe_http_auth,
                 https_only: config.https_only,
+                request_hook: config.request_hook,
+                response_hook: config.response_hook,
+                response_body_hook: config.response_body_hook,
             }),
         })
     }
@@ -1889,6 +1899,24 @@ impl ClientBuilder {
         self.config.quic_send_window = Some(value);
         self
     }
+
+    /// Set request hook
+    pub fn request_hook(mut self, hook: Arc<dyn RequestHook>) -> ClientBuilder {
+        self.config.request_hook = Some(hook);
+        self
+    }
+
+    /// Set response hook
+    pub fn response_hook(mut self, hook: Arc<dyn ResponseHook>) -> ClientBuilder {
+        self.config.response_hook = Some(hook);
+        self
+    }
+
+    /// Set response body hook
+    pub fn response_body_hook(mut self, hook: Arc<dyn ResponseBodyHook>) -> ClientBuilder {
+        self.config.response_body_hook = Some(hook);
+        self
+    }
 }
 
 type HyperClient = hyper_util::client::legacy::Client<Connector, super::Body>;
@@ -2007,6 +2035,11 @@ impl Client {
     }
 
     pub(super) fn execute_request(&self, req: Request) -> Pending {
+        let req = if let Some(req_hook) = self.inner.request_hook.as_ref() {
+            req_hook.intercept(req)
+        } else {
+            req
+        };
         let (method, url, mut headers, body, timeout, version) = req.pieces();
         if url.scheme() != "http" && url.scheme() != "https" {
             return Pending::new_err(error::url_bad_scheme(url));
@@ -2105,6 +2138,8 @@ impl Client {
                 total_timeout,
                 read_timeout_fut,
                 read_timeout: self.inner.read_timeout,
+                response_hook: self.inner.response_hook.clone(),
+                response_body_hook: self.inner.response_body_hook.clone(),
             }),
         }
     }
@@ -2314,6 +2349,9 @@ struct ClientRef {
     proxies: Arc<Vec<Proxy>>,
     proxies_maybe_http_auth: bool,
     https_only: bool,
+    request_hook: Option<Arc<dyn RequestHook>>,
+    response_hook: Option<Arc<dyn ResponseHook>>,
+    response_body_hook: Option<Arc<dyn ResponseBodyHook>>,
 }
 
 impl ClientRef {
@@ -2379,6 +2417,9 @@ pin_project! {
 
         client: Arc<ClientRef>,
 
+        response_hook: Option<Arc<dyn ResponseHook>>,
+        response_body_hook: Option<Arc<dyn ResponseBodyHook>>,
+
         #[pin]
         in_flight: ResponseFuture,
         #[pin]
@@ -2745,7 +2786,13 @@ impl Future for PendingRequest {
                 self.client.accepts,
                 self.total_timeout.take(),
                 self.read_timeout,
+                self.response_body_hook.clone(),
             );
+            let res = if let Some(res_hook) = self.response_hook.as_ref() {
+                res_hook.intercept(res)
+            } else {
+                res
+            };
             return Poll::Ready(Ok(res));
         }
     }

src/async_impl/hooks.rs

@@ -0,0 +1,21 @@
+//! Hooks to intercept the request, response and response body
+
+use super::{Request, Response};
+
+/// Hook that gets called before sending the request, right after it's constructed
+pub trait RequestHook: Send + Sync {
+    /// Intercept the request and return it with or without changes
+    fn intercept(&self, req: Request) -> Request;
+}
+
+/// Hook that gets called once the request is completed and headers have been received
+pub trait ResponseHook: Send + Sync {
+    /// Intercept the response and return it with or without changes
+    fn intercept(&self, res: Response) -> Response;
+}
+
+/// Hook that gets called once the request is completed and the full body has been received
+pub trait ResponseBodyHook: Send + Sync {
+    /// Intercept the response body and return it with or without changes
+    fn intercept(&self, body: String) -> String;
+}

src/async_impl/mod.rs

@@ -10,6 +10,8 @@ pub(crate) use self::decoder::Decoder;
 pub mod body;
 pub mod client;
 pub mod decoder;
+pub mod hooks;
+
 pub mod h3_client;
 #[cfg(feature = "multipart")]
 pub mod multipart;

src/async_impl/response.rs

@@ -1,6 +1,7 @@
 use std::fmt;
 use std::net::SocketAddr;
 use std::pin::Pin;
+use std::sync::Arc;
 use std::time::Duration;
 
 use bytes::Bytes;
@@ -16,6 +17,7 @@ use url::Url;
 
 use super::body::Body;
 use super::decoder::{Accepts, Decoder};
+use super::hooks::ResponseBodyHook;
 use crate::async_impl::body::ResponseBody;
 #[cfg(feature = "cookies")]
 use crate::cookie;
@@ -31,6 +33,7 @@ pub struct Response {
     // Boxed to save space (11 words to 1 word), and it's not accessed
     // frequently internally.
     url: Box<Url>,
+    response_body_hook: Option<Arc<dyn ResponseBodyHook>>,
 }
 
 impl Response {
@@ -40,6 +43,7 @@ impl Response {
         accepts: Accepts,
         total_timeout: Option<Pin<Box<Sleep>>>,
         read_timeout: Option<Duration>,
+        response_body_hook: Option<Arc<dyn ResponseBodyHook>>,
     ) -> Response {
         let (mut parts, body) = res.into_parts();
         let decoder = Decoder::detect(
@@ -52,6 +56,7 @@ impl Response {
         Response {
             res,
             url: Box::new(url),
+            response_body_hook,
         }
     }
 
@@ -215,10 +220,16 @@ impl Response {
             .unwrap_or(default_encoding);
         let encoding = Encoding::for_label(encoding_name.as_bytes()).unwrap_or(UTF_8);
 
+        let res_body_hook = self.response_body_hook.clone();
         let full = self.bytes().await?;
 
         let (text, _, _) = encoding.decode(&full);
-        Ok(text.into_owned())
+        let text = if let Some(res_body_hook) = res_body_hook.as_ref() {
+            res_body_hook.intercept(text.into_owned())
+        } else {
+            text.into_owned()
+        };
+        Ok(text)
     }
 
     /// Try to deserialize the response body as JSON.
@@ -468,6 +479,7 @@ impl<T: Into<Body>> From<http::Response<T>> for Response {
         Response {
             res,
             url: Box::new(url),
+            response_body_hook: None,
         }
     }
 }

src/lib.rs

@@ -352,6 +352,7 @@ if_hyper! {
     #[cfg(feature = "multipart")]
     pub use self::async_impl::multipart;
 
+    pub use self::async_impl::hooks;
 
     mod async_impl;
     #[cfg(feature = "blocking")]

tests/hooks.rs

@@ -0,0 +1,68 @@
+#![cfg(not(target_arch = "wasm32"))]
+#![cfg(not(feature = "rustls-tls-manual-roots-no-provider"))]
+mod support;
+
+use std::sync::{Arc, Mutex};
+
+use support::server;
+
+use reqwest::{
+    hooks::{RequestHook, ResponseBodyHook, ResponseHook},
+    Client,
+};
+
+#[derive(Default)]
+struct MyHook {
+    pub req_visited: Arc<Mutex<bool>>,
+    pub res_visited: Arc<Mutex<bool>>,
+    pub body_visited: Arc<Mutex<bool>>,
+}
+
+impl RequestHook for MyHook {
+    fn intercept(&self, req: reqwest::Request) -> reqwest::Request {
+        *self.req_visited.lock().unwrap() = true;
+        req
+    }
+}
+
+impl ResponseHook for MyHook {
+    fn intercept(&self, res: reqwest::Response) -> reqwest::Response {
+        *self.res_visited.lock().unwrap() = true;
+        res
+    }
+}
+
+impl ResponseBodyHook for MyHook {
+    fn intercept(&self, body: String) -> String {
+        *self.body_visited.lock().unwrap() = true;
+        body
+    }
+}
+
+#[tokio::test]
+async fn full_hook_chain() {
+    let _ = env_logger::try_init();
+
+    let server = server::http(move |_req| async { http::Response::new("Hello".into()) });
+
+    let hook = Arc::new(MyHook::default());
+
+    let client = Client::builder()
+        .request_hook(hook.clone())
+        .response_hook(hook.clone())
+        .response_body_hook(hook.clone())
+        .build()
+        .unwrap();
+
+    let res = client
+        .get(&format!("http://{}/text", server.addr()))
+        .send()
+        .await
+        .expect("Failed to get");
+    assert_eq!(res.content_length(), Some(5));
+    let text = res.text().await.expect("Failed to get text");
+    assert_eq!("Hello", text);
+    assert!(*hook.req_visited.lock().unwrap());
+    assert!(*hook.res_visited.lock().unwrap());
+    assert!(*hook.body_visited.lock().unwrap());
+}