How do I return an arbitrary status code with an Optional message?

[thomasmost]

How do I return a response from an API handler with an arbitrary error status and an arbitrary error message?

I currently make use of response statuses in two ways in my app, with rocket::http::Status and rocket::response::status. In the former case, I can return any error status I want, but I can't pass down a custom error message with it. See below:

use rocket::http::Status;

#[get("/hello1")]
pub async fn hello_any_status(
  db_pool: &State<Pool>,
) -> Result<Json<String>, Status> {
  ...
  return Err(Status::BadRequest)
}

...and in the latter case, I can pass a custom message, but the only supported error status code is BadRequest

use rocket::response::status;

#[get("/hello2")]
pub fn hello_with_bad_request(
  db_pool: &State<Pool>,
) -> Result<Json<String>, status::BadRequest<String>> {
  ...
  return Err(BadRequest(Some("Your name must be longer than 3 characters")))
}

What's the difference between rocket::http::Status and rocket::response::status, and how can I respond with any appropriate status code AND an optional message?

Thanks in advance 🚀

[the10thWiz]

There are a number of options. I recommend deriving Responder on an enum, which allows you to set a custom status & responder. For a simple case, you can return (http::Status, R), where R implements Responder. This will set the status code and return the content of R.

The enum case should looks something like:

#[derive(Responder)]
pub enum ApiResponse<T> {
  Ok(T),
  #[response(status = 400)]
  BadRequest(String),
  #[response(status = 401)]
  Unauthorized(String),
  #[response(status = 403)]
  Forbidden(String),
}

Then, ApiResponse can be used in place of Result.