Cannot access State in a FromRequestParts implementation

[evgenykobz]

Summary

When I attempt to extract value in a handler like so...

handler.rs

pub async fn sign_in(
    custom::extract::User(user): custom::extract::User,

...error below is raised:

the trait bound state::State: FromRef<()> is not satisfied.

My initial attempt to implement FromRequestParts:

extract.rs

    #[axum::async_trait]
    impl axum::extract::FromRequestParts<custom::state::State> for User {
        type Rejection = custom::error::Error;

        async fn from_request_parts(
            mut parts: &mut axum::http::request::Parts,
            state: &custom::state::State,
        ) -> Result<Self, Self::Rejection> {

After some back-and-forth I came up with the second attempt to no avail:

extract.rs

    #[axum::async_trait]
    impl<S> axum::extract::FromRequestParts<S> for User
    where
        custom::state::State: axum::extract::FromRef<S>,
        S: Send + Sync,
    {
        type Rejection = custom::error::Error;

        async fn from_request_parts(
            mut parts: &mut axum::http::request::Parts,
            state: &S,
        ) -> Result<Self, Self::Rejection> {
            let state = parts
                .extract_with_state::<axum::extract::State<modules::state::State>>(state)
                .await?;

I feel like my error is unrelated to FromRequestParts implementation, maybe there is something wrong with my Router setup.

main.rs

let app = NormalizePathLayer::trim_trailing_slash().layer(
            routes::router(&self.assets_path)
                .with_state(state)
                .layer(middlewares),
        );

routes.rs

pub fn router<'a>(assets_path: &'a str) -> axum::Router<custom::state::State> {
    axum::Router::new().nest("/auth", auth::router())

auth.rs

pub fn router() -> axum::Router<custom::state::State> {
    axum::Router::new()
        .route("/", axum::routing::post(handler::sign_in)) // See handler.rs snippet above

axum version

0.7.5

[evgenykobz]

Btw my state is:

#[derive(Clone, Debug)]
pub struct State(pub Arc<Inner>);

[jplatte]

Could it be that you're using #[debug_handler] on your handler function without specifying the state type? It will only be inferred if you use the State extractor.

[evgenykobz]

Could it be that you're using #[debug_handler] on your handler function without specifying the state type? It will only be inferred if you use the State extractor.

Yeah, indeed. For the future generations: have a look at this debug_handler section.