chore: move new() to Backend trait

Author: yannham

libdd-http-client/src/backend/hyper_backend.rs

@@ -25,14 +25,6 @@ impl std::fmt::Debug for HyperBackend {
 
 #[cfg(feature = "hyper-backend")]
 impl HyperBackend {
-    pub(crate) fn new(
-        _timeout: std::time::Duration,
-        transport: TransportConfig,
-    ) -> Result<Self, HttpClientError> {
-        let client = http_common::client_builder().build(Connector::default());
-        Ok(Self { client, transport })
-    }
-
     /// Rewrite the request URL for UDS/Named Pipe transports.
     fn rewrite_url(&self, url: &str) -> Result<hyper::Uri, HttpClientError> {
         match &self.transport {
@@ -156,6 +148,14 @@ fn map_hyper_error(e: hyper_util::client::legacy::Error) -> HttpClientError {
 
 #[cfg(feature = "hyper-backend")]
 impl super::Backend for HyperBackend {
+    fn new(
+        _timeout: std::time::Duration,
+        transport: TransportConfig,
+    ) -> Result<Self, HttpClientError> {
+        let client = http_common::client_builder().build(Connector::default());
+        Ok(Self { client, transport })
+    }
+
     async fn send(
         &self,
         mut request: HttpRequest,

libdd-http-client/src/backend/mod.rs

@@ -1,6 +1,9 @@
 // Copyright 2026-Present Datadog, Inc. https://www.datadoghq.com/
 // SPDX-License-Identifier: Apache-2.0
 
+use crate::{config, HttpClientError, HttpRequest, HttpResponse};
+use std::time::Duration;
+
 #[cfg(all(feature = "hyper-backend", not(feature = "reqwest-backend")))]
 pub(crate) mod hyper_backend;
 #[cfg(feature = "reqwest-backend")]
@@ -9,13 +12,16 @@ pub(crate) mod reqwest_backend;
 /// The internal async transport backend.
 ///
 /// This trait uses native AFIT (stable since Rust 1.75, MSRV is 1.84.1).
-/// It is intentionally not object-safe — `HttpClient` holds a concrete backend
-/// type, never a `dyn Backend`.
-pub(crate) trait Backend {
+/// It is intentionally not object-safe — [HttpClient] holds a concrete backend type, never a `dyn
+/// Backend`.
+pub(crate) trait Backend: Sized {
+    /// Construct a new backend with the given timeout and transport.
+    fn new(timeout: Duration, transport: config::TransportConfig) -> Result<Self, HttpClientError>;
+
     /// Send an HTTP request and return the response.
     async fn send(
         &self,
-        request: crate::HttpRequest,
-        config: &crate::config::HttpClientConfig,
-    ) -> Result<crate::HttpResponse, crate::HttpClientError>;
+        request: HttpRequest,
+        config: &config::HttpClientConfig,
+    ) -> Result<HttpResponse, HttpClientError>;
 }

libdd-http-client/src/backend/reqwest_backend.rs

@@ -17,11 +17,9 @@ pub(crate) struct ReqwestBackend {
 }
 
 #[cfg(feature = "reqwest-backend")]
-impl ReqwestBackend {
-    /// Construct a new backend with the given timeout and transport.
-    ///
-    /// Creates a `reqwest::Client` with connection pooling enabled.
-    pub(crate) fn new(
+impl super::Backend for ReqwestBackend {
+    // Creates a `reqwest::Client` with connection pooling enabled.
+    fn new(
         timeout: std::time::Duration,
         transport: TransportConfig,
     ) -> Result<Self, HttpClientError> {
@@ -44,10 +42,7 @@ impl ReqwestBackend {
             .map_err(|e| HttpClientError::InvalidConfig(e.to_string()))?;
         Ok(Self { client })
     }
-}
 
-#[cfg(feature = "reqwest-backend")]
-impl super::Backend for ReqwestBackend {
     async fn send(
         &self,
         request: HttpRequest,