Cannot compile handler with both ConnectInfo and Form extractors

[thomas-huegel]

Bug Report

Version

axum v0.6.20

Platform

Linux archlinux 6.4.8-arch1-Yagakimi-T2-1-t2 #1 SMP PREEMPT_DYNAMIC Fri, 04 Aug 2023 14:49:02 +0000 x86_64 GNU/Linux

Description

I cannot compile with both ConnectInfo and Form extractors, whereas they compile separately.

use axum::{extract::ConnectInfo, routing::post, Form, Router};

use std::net::SocketAddr;

#[derive(serde::Deserialize)]
pub struct LoginForm {
    username: String,
}

async fn truc() {
    let app = Router::new().route("/", post(handler));

    async fn handler(
        Form(_form): Form<LoginForm>,
        ConnectInfo(_addr): ConnectInfo<SocketAddr>,
    ) -> String {
        format!("Hello")
    }

    axum::Server::bind(&"0.0.0.0:3000".parse().unwrap())
        .serve(app.into_make_service_with_connect_info::<SocketAddr>())
        .await
        .expect("server failed");
}

If I remove either _form or _addr from the arguments of handler, it compiles.
Otherwise I get the following error message :

error[E0277]: the trait bound `fn(axum::Form<pb_with_connect_info::LoginForm>, ConnectInfo<std::net::SocketAddr>) -> impl std::future::Future<Output = std::string::String> {handler}: axum::handler::Handler<_, _, _>` is not satisfied
   --> src/pb_with_connect_info.rs:13:45
    |
13  |     let app = Router::new().route("/", post(handler));
    |                                        ---- ^^^^^^^ the trait `axum::handler::Handler<_, _, _>` is not implemented for fn item `fn(axum::Form<pb_with_connect_info::LoginForm>, ConnectInfo<std::net::SocketAddr>) -> impl std::future::Future<Output = std::string::String> {handler}`
    |                                        |
    |                                        required by a bound introduced by this call
    |
    = help: the following other types implement trait `axum::handler::Handler<T, S, B>`:
              <axum_extra::handler::or::Or<L, R, Lt, Rt, S, B> as axum::handler::Handler<(M, Lt, Rt), S, B>>
              <axum_extra::handler::IntoHandler<H, T, S, B> as axum::handler::Handler<T, S, B>>
              <axum::handler::Layered<L, H, T, S, B, B2> as axum::handler::Handler<T, S, B2>>
              <MethodRouter<S, B> as axum::handler::Handler<(), S, B>>
note: required by a bound in `axum::routing::post`
   --> /home/thomas/.cargo/registry/src/index.crates.io-6f17d22bba15001f/axum-0.6.20/src/routing/method_routing.rs:407:1
    |
407 | top_level_handler_fn!(post, POST);
    | ^^^^^^^^^^^^^^^^^^^^^^----^^^^^^^
    | |                     |
    | |                     required by a bound in this function
    | required by this bound in `post`
    = note: this error originates in the macro `top_level_handler_fn` (in Nightly builds, run with -Z macro-backtrace for more info)

Thanks for your help!

[davidpdrsn]

Try https://docs.rs/axum/0.6.20/axum/attr.debug_handler.html