Handler<_, _>` is not satisfied

[DoneDeal0]

Summary

Hello, I'm trying to test a route in axum. But I can't do it because of the line:

 let app = Router::new().route("/login", post(login));

that returns the error:

the trait bound fn(axum::Json<AuthPayload>) -> impl Future<Output = (axum::http::StatusCode, CookieJar, axum::Json<serde_json::Value>)> {router::auth::login::login}: Handler<_, _> is not satisfied

Honestly, it's completely cryptic. Is it possible to fix it, and if so, how? Here is the code:

use axum::{Json, http::StatusCode, response::IntoResponse};
use axum_extra::extract::{CookieJar, cookie::Cookie};
use serde_json::json;

use crate::{
    middleware::jwt_cookie::create_jwt,
    models::{auth::AuthPayload, user::User},
};

pub async fn login(
    Json(payload): Json<AuthPayload>,
) -> (StatusCode, CookieJar, Json<serde_json::Value>) {
    let email = payload.email;
    let password = payload.password;

    let mut jar = CookieJar::new();

    if email == "test@example.com" && password == "password123" {
        let user = User::get("123", "testuser", "https://avatar.com/image.png");
        let token = create_jwt(&user.id, &user.name, &user.avatar_url);

        let cookie = Cookie::build(("token", token))
            .http_only(true)
            .path("/")
            .build();

        jar = jar.add(cookie);

        (StatusCode::OK, jar, Json(json!(user)))
    } else {
        (
            StatusCode::UNAUTHORIZED,
            jar, // Empty jar since login failed
            Json(json!({ "error": "Invalid credentials" })),
        )
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use axum::{Router, http::StatusCode, routing::post};
    use axum_test::TestServer;
    use serde_json::json;

    #[tokio::test]
    async fn test_successful_login() {
        let app = Router::new().route("/login", post(login));
        let server = TestServer::new(app).unwrap();

        let payload = json!({
            "email": "test@example.com",
            "password": "password123"
        });

        let response = server.post("/login").json(&payload).await;

        response.assert_status(StatusCode::OK);

        let json_response = response.json();
        assert_eq!(json_response["id"], "123");
        assert_eq!(json_response["name"], "testuser");
        assert_eq!(json_response["avatar_url"], "https://avatar.com/image.png");

        // Check that the response contains a `Set-Cookie` header for the token
        let cookie = response.headers().get("set-cookie").unwrap();
        assert!(cookie.to_str().unwrap().contains("token="));
    }

    #[tokio::test]
    async fn test_failed_login() {
        let app = Router::new().route("/login", axum::routing::post(login));
        let server = TestServer::new(app).unwrap();

        let payload = json!({
            "email": "wrong@example.com",
            "password": "wrongpassword"
        });

        let response = server.post("/login").json(&payload).await;

        response.assert_status(StatusCode::UNAUTHORIZED);
        let json_response = response.json();
        assert_eq!(json_response["error"], "Invalid credentials");
    }
}

axum version

0.8.1

[yanns]

Have you tried using https://docs.rs/axum-macros/latest/axum_macros/attr.debug_handler.html ?

[DoneDeal0]

Thank you! I didn't know this macro! Life saving!