shoutdotdev/src/app_error.rs

use anyhow::Error;
use axum::http::StatusCode;
use axum::response::{IntoResponse, Response};

// Use anyhow, define error and enable '?'
// For a simplified example of using anyhow in axum check /examples/anyhow-error-response
#[derive(Debug)]
pub enum AppError {
    InternalServerError(Error),
    ForbiddenError(String),
}

// Tell axum how to convert `AppError` into a response.
impl IntoResponse for AppError {
    fn into_response(self) -> Response {
        match self {
            Self::InternalServerError(err) => {
                tracing::error!("Application error: {:?}", err);
                (StatusCode::INTERNAL_SERVER_ERROR, "Something went wrong").into_response()
            }
            Self::ForbiddenError(client_message) => {
                tracing::info!("Forbidden: {}", client_message);
                (StatusCode::FORBIDDEN, client_message).into_response()
            }
        }
    }
}

// This enables using `?` on functions that return `Result<_, anyhow::Error>` to turn them into
// `Result<_, AppError>`. That way you don't need to do that manually.
impl<E> From<E> for AppError
where
    E: Into<anyhow::Error>,
{
    fn from(err: E) -> Self {
        Self::InternalServerError(Into::<anyhow::Error>::into(err))
    }
}