add 500 catcher

src/main.rs

@@ -38,6 +38,8 @@ impl<T, E> ErrorEmpty for Result<T, E> {
 enum WebError {
     #[response(status = 404)]
     NotFound(Template),
+    #[response(status = 500)]
+    ServerError(Template),
 }
 
 impl WebError {
@@ -45,6 +47,10 @@ impl WebError {
         let context: HashMap<String, String> = HashMap::new();
         WebError::NotFound(Template::render("404", context))
     }
+    fn server_error() -> Self {
+        let context: HashMap<String, String> = HashMap::new();
+        WebError::ServerError(Template::render("500", context))
+    }
 }
 
 #[derive(Clone)]
@@ -161,6 +167,11 @@ fn not_found(_req: &rocket::Request) -> WebError {
     WebError::not_found()
 }
 
+#[catch(500)]
+fn server_error(_req: &rocket::Request) -> WebError {
+    WebError::server_error()
+}
+
 #[launch]
 async fn rocket() -> _ {
     let state: AppState = async_db::Reader::new(DB_FILENAME)
@@ -175,7 +186,7 @@ async fn rocket() -> _ {
     rocket::build()
         .manage(state)
         .manage(cache)
-        .register("/", catchers![not_found])
+        .register("/", catchers![not_found, server_error])
         .mount(
             "/",
             routes![index, show_question, show_answer, question0, answer0],