Axum Extractor

Components implements the shape Axum's FromRequestParts needs, so use it directly as router state, and pull dependencies out of handlers with Inject<T>:

use axum::{Router, routing::get};
use axumstart_components::{ComponentProvider, axum::Inject};
use std::sync::Arc;

async fn handler(db: Inject<Database>) -> String {
    db.query_count.load(Ordering::Relaxed).to_string()
}

async fn build_app() -> Router {
    let ctx = ComponentProvider::default();
    ctx.register_all();
    let components = ctx.build().await;

    Router::new()
        .route("/", get(handler))
        .with_state(components)
}

Inject<T> rejects with a String (used as the Axum rejection body) naming the missing type if T was never registered — this only happens if the component is missing from the container, not per-request.