#[macro_use] extern crate rocket;

#[derive(serde::Deserialize, validator::Validate, rocketjson::JsonBody)]
pub struct RegisterRequest {
   #[validate(length(min = 1))]
   username: String 
}

#[derive(serde::Serialize)]
pub struct RegisterResponse {
   message: String
}

#[post("/register", data="<data>")]
pub fn register(data: RegisterRequest) -> rocketjson::ApiResponse<RegisterResponse> {
   rocketjson::ApiResponse::new(rocket::http::Status::Ok, RegisterResponse { message: format!("Welcome {}", data.username) })
}

#[launch]
fn rocket() -> _ {
    rocket::build()
        .mount("/", routes![register]).
        register("/", vec![rocketjson::error::get_catcher()])
}

{
    "username": "testuser"
}

{
    "message": "Welcome testuser"
}

{
    "username": ""
}

{
    "username": [
        {
            "code": "length",
            "message": null,
            "params": {
                "value": "",
                "min": 1
            }
        }
    ]
}