Улучшенное отображение ошибок при обновлении ссылки расписания.

src/xls_downloader/interface.rs

@@ -1,23 +1,32 @@
 use chrono::{DateTime, Utc};
+use derive_more::Display;
 use std::mem::discriminant;
+use std::sync::Arc;
+use utoipa::ToSchema;
 
 /// XLS data retrieval errors.
-#[derive(Debug)]
+#[derive(Clone, Debug, ToSchema, Display)]
 pub enum FetchError {
     /// File url is not set.
+    #[display("The link to the timetable was not provided earlier.")]
     NoUrlProvided,
 
     /// Unknown error.
-    Unknown(reqwest::Error),
+    #[display("An unknown error occurred while downloading the file.")]
+    #[schema(value_type = String)]
+    Unknown(Arc<reqwest::Error>),
 
     /// Server returned a status code different from 200.
-    BadStatusCode,
+    #[display("Server returned a status code {_0}.")]
+    BadStatusCode(u16),
 
     /// The url leads to a file of a different type.
-    BadContentType,
+    #[display("The link leads to a file of type '{_0}'.")]
+    BadContentType(String),
 
     /// Server doesn't return expected headers.
-    BadHeaders,
+    #[display("Server doesn't return expected header(s) '{_0}'.")]
+    BadHeaders(String),
 }
 
 impl PartialEq for FetchError {