Optionally record redirect history

src/config.rs

@@ -145,6 +145,7 @@ pub struct Config {
     max_redirects: u32,
     max_redirects_will_error: bool,
     redirect_auth_headers: RedirectAuthHeaders,
+    save_redirect_history: bool,
     user_agent: AutoHeaderValue,
     accept: AutoHeaderValue,
     accept_encoding: AutoHeaderValue,
@@ -277,6 +278,17 @@ impl Config {
         self.redirect_auth_headers
     }
 
+    /// If we should record a history of every redirect location,
+    /// including the request and final locations.
+    ///
+    /// Comes at the cost of allocating/retaining the Uri for
+    /// every redirect loop.
+    ///
+    /// Defaults to false
+    pub fn save_redirect_history(&self) -> bool {
+        self.save_redirect_history
+    }
+
     /// Value to use for the `User-Agent` header.
     ///
     /// This can be overridden by setting a `user-agent` header on the request
@@ -482,6 +494,18 @@ impl<Scope: private::ConfigScope> ConfigBuilder<Scope> {
         self
     }
 
+    /// If we should record a history of every redirect location,
+    /// including the request and final locations.
+    ///
+    /// Comes at the cost of allocating/retaining the Uri for
+    /// every redirect loop.
+    ///
+    /// Defaults to false
+    pub fn save_redirect_history(mut self, v: bool) -> Self {
+        self.config().save_redirect_history = v;
+        self
+    }
+
     /// Value to use for the `User-Agent` header.
     ///
     /// This can be overridden by setting a `user-agent` header on the request
@@ -809,6 +833,7 @@ impl Default for Config {
             max_redirects: 10,
             max_redirects_will_error: true,
             redirect_auth_headers: RedirectAuthHeaders::Never,
+            save_redirect_history: false,
             user_agent: AutoHeaderValue::default(),
             accept: AutoHeaderValue::default(),
             accept_encoding: AutoHeaderValue::default(),
@@ -884,6 +909,7 @@ impl fmt::Debug for Config {
             .field("no_delay", &self.no_delay)
             .field("max_redirects", &self.max_redirects)
             .field("redirect_auth_headers", &self.redirect_auth_headers)
+            .field("save_redirect_history", &self.save_redirect_history)
             .field("user_agent", &self.user_agent)
             .field("timeouts", &self.timeouts)
             .field("max_response_header_size", &self.max_response_header_size)

src/lib.rs

@@ -847,6 +847,65 @@ pub(crate) mod test {
         assert_eq!(response_uri.path(), "/get")
     }
 
+    #[test]
+    fn redirect_history_none() {
+        init_test_log();
+        let res = get("http://httpbin.org/redirect-to?url=%2Fget")
+            .call()
+            .unwrap();
+        let redirect_history = res.get_redirect_history();
+        assert_eq!(redirect_history, None)
+    }
+
+    #[test]
+    fn redirect_history_some() {
+        init_test_log();
+        let agent: Agent = Config::builder()
+            .max_redirects(3)
+            .max_redirects_will_error(false)
+            .save_redirect_history(true)
+            .build()
+            .into();
+        let res = agent
+            .get("http://httpbin.org/redirect-to?url=%2Fget")
+            .call()
+            .unwrap();
+        let redirect_history = res.get_redirect_history();
+        assert_eq!(
+            redirect_history,
+            Some(
+                vec![
+                    "http://httpbin.org/redirect-to?url=%2Fget".parse().unwrap(),
+                    "http://httpbin.org/get".parse().unwrap()
+                ]
+                .as_ref()
+            )
+        );
+        let res = agent
+            .get(
+                "http://httpbin.org/redirect-to?url=%2Fredirect-to%3F\
+                url%3D%2Fredirect-to%3Furl%3D%252Fredirect-to%253Furl%253D",
+            )
+            .call()
+            .unwrap();
+        let redirect_history = res.get_redirect_history();
+        assert_eq!(
+            redirect_history,
+            Some(vec![
+                "http://httpbin.org/redirect-to?url=%2Fredirect-to%3Furl%3D%2Fredirect-to%3Furl%3D%252Fredirect-to%253Furl%253D".parse().unwrap(),
+                "http://httpbin.org/redirect-to?url=/redirect-to?url=%2Fredirect-to%3Furl%3D".parse().unwrap(),
+                "http://httpbin.org/redirect-to?url=/redirect-to?url=".parse().unwrap(),
+                "http://httpbin.org/redirect-to?url=".parse().unwrap(),
+            ].as_ref())
+        );
+        let res = agent.get("https://www.google.com/").call().unwrap();
+        let redirect_history = res.get_redirect_history();
+        assert_eq!(
+            redirect_history,
+            Some(vec!["https://www.google.com/".parse().unwrap()].as_ref())
+        );
+    }
+
     #[test]
     fn connect_https_invalid_name() {
         let result = get("https://example.com{REQUEST_URI}/").call();

src/response.rs

@@ -6,12 +6,20 @@ use crate::http;
 #[derive(Debug, Clone)]
 pub(crate) struct ResponseUri(pub http::Uri);
 
+#[derive(Debug, Clone)]
+pub(crate) struct RedirectHistory(pub Vec<Uri>);
+
 /// Extension trait for `http::Response<Body>` objects
 ///
 /// Allows the user to access the `Uri` in http::Response
 pub trait ResponseExt {
     /// The Uri we ended up at. This can differ from the request uri when we have followed redirects.
     fn get_uri(&self) -> &Uri;
+
+    /// The full history of uris, including the request and final uri.
+    ///
+    /// Returns None when `save_redirect_history` is false.
+    fn get_redirect_history(&self) -> Option<&[Uri]>;
 }
 
 impl ResponseExt for http::Response<Body> {
@@ -22,4 +30,10 @@ impl ResponseExt for http::Response<Body> {
             .expect("uri to have been set")
             .0
     }
+
+    fn get_redirect_history(&self) -> Option<&[Uri]> {
+        self.extensions()
+            .get::<RedirectHistory>()
+            .map(|r| r.0.as_ref())
+    }
 }

src/run.rs

@@ -14,7 +14,7 @@ use crate::body::ResponseInfo;
 use crate::config::{Config, RequestLevelConfig, DEFAULT_USER_AGENT};
 use crate::http;
 use crate::pool::Connection;
-use crate::response::ResponseUri;
+use crate::response::{RedirectHistory, ResponseUri};
 use crate::timings::{CallTimings, CurrentTime};
 use crate::transport::time::{Duration, Instant};
 use crate::transport::ConnectionDetails;
@@ -41,6 +41,9 @@ pub(crate) fn run(
         .map(Arc::new)
         .unwrap_or_else(|| agent.config.clone());
 
+    let mut redirect_history: Option<Vec<Uri>> =
+        config.save_redirect_history().then_some(Vec::new());
+
     let timeouts = config.timeouts();
 
     let mut timings = CallTimings::new(timeouts, CurrentTime::default());
@@ -67,6 +70,7 @@ pub(crate) fn run(
             flow,
             &mut body,
             redirect_count,
+            &mut redirect_history,
             &mut timings,
         )? {
             // Follow redirect
@@ -112,6 +116,7 @@ fn flow_run(
     mut flow: Flow<Prepare>,
     body: &mut SendBody,
     redirect_count: u32,
+    redirect_history: &mut Option<Vec<Uri>>,
     timings: &mut CallTimings,
 ) -> Result<FlowResult, Error> {
     let uri = flow.uri().clone();
@@ -166,6 +171,12 @@ fn flow_run(
         jar.store_response_cookies(iter, &uri);
     }
 
+    if let Some(history) = redirect_history.as_mut() {
+        history.push(uri.clone());
+        response
+            .extensions_mut()
+            .insert(RedirectHistory(history.clone()));
+    }
     response.extensions_mut().insert(ResponseUri(uri));
 
     let ret = match response_result {