katbin/src/api/catchers/mod.rs

use rocket::Rocket;
use rocket::response::status;
use rocket::http::Status;
use rocket_contrib::json::Json;
use serde_json::Value;

#[catch(404)]
fn not_found() -> status::Custom<Json<Value>> {
    status::Custom(Status::NotFound, Json(json!({
        "err":"route not found",
        "msg": "The given route does not exist"
    })))
}

#[catch(422)]
fn unprocessable_entity() -> status::Custom<Json<Value>> {
    status::Custom(Status::UnprocessableEntity, Json(json!({
        "err":"failed to process entity",
        "msg": "The given object could not be processed. This could be due to sending \
         malformed or incomplete JSON objects in the request body."
    })))
}

#[catch(500)]
fn internal_server_error() -> status::Custom<Json<Value>> {
    status::Custom(Status::NotFound, Json(json!({
        "err":"internal server error",
        "msg": "Something went wrong, try again"
    })))
}

pub fn fuel(rocket: Rocket) -> Rocket {
    rocket.register(catchers![not_found, unprocessable_entity, internal_server_error])
}