Make ResponseBuilderExt not target-dependent

src/response.rs

@@ -0,0 +1,41 @@
+use url::Url;
+
+#[derive(Debug, Clone, PartialEq)]
+pub(crate) struct ResponseUrl(pub Url);
+
+/// Extension trait for http::response::Builder objects
+///
+/// Allows the user to add a `Url` to the http::Response
+pub trait ResponseBuilderExt {
+    /// A builder method for the `http::response::Builder` type that allows the user to add a `Url`
+    /// to the `http::Response`
+    fn url(self, url: Url) -> Self;
+}
+
+impl ResponseBuilderExt for http::response::Builder {
+    fn url(self, url: Url) -> Self {
+        self.extension(ResponseUrl(url))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{ResponseBuilderExt, ResponseUrl};
+    use http::response::Builder;
+    use url::Url;
+
+    #[test]
+    fn test_response_builder_ext() {
+        let url = Url::parse("http://example.com").unwrap();
+        let response = Builder::new()
+            .status(200)
+            .url(url.clone())
+            .body(())
+            .unwrap();
+
+        assert_eq!(
+            response.extensions().get::<ResponseUrl>(),
+            Some(&ResponseUrl(url))
+        );
+    }
+}