return a localized error for all error kinds

some errors are not yet localized, but now the Python code
doesn't need to think about which property to use

proto/backend.proto

@@ -73,13 +73,16 @@ message BackendOutput {
 }
 
 message BackendError {
+    // localized error description suitable for displaying to the user
+    string localized = 1;
+    // error specifics
     oneof value {
-        StringError invalid_input = 1;
-        TemplateParseError template_parse = 2;
-        StringError io_error = 3;
-        StringError db_error = 4;
-        NetworkError network_error = 5;
-        SyncError sync_error = 6;
+        StringError invalid_input = 2;
+        StringError template_parse = 3;
+        StringError io_error = 4;
+        StringError db_error = 5;
+        NetworkError network_error = 6;
+        SyncError sync_error = 7;
         // user interrupted operation
         Empty interrupted = 8;
     }
@@ -96,10 +99,6 @@ message StringError {
     string info = 1;
 }
 
-message TemplateParseError {
-    string info = 1;
-}
-
 message NetworkError {
     string info = 1;
     enum NetworkErrorKind {
@@ -109,7 +108,6 @@ message NetworkError {
         PROXY_AUTH = 3;
     }
     NetworkErrorKind kind = 2;
-    string localized = 3;
 }
 
 message SyncError {
@@ -125,7 +123,6 @@ message SyncError {
         RESYNC_REQUIRED = 7;
     }
     SyncErrorKind kind = 2;
-    string localized = 3;
 }
 
 message MediaSyncProgress {

pylib/anki/rsbackend.py

@@ -32,14 +32,17 @@ class StringError(Exception):
 
 
 NetworkErrorKind = pb.NetworkError.NetworkErrorKind
+SyncErrorKind = pb.SyncError.SyncErrorKind
 
 
 class NetworkError(StringError):
     def kind(self) -> NetworkErrorKind:
         return self.args[1]
 
-    def localized(self) -> str:
-        return self.args[2]
+
+class SyncError(StringError):
+    def kind(self) -> SyncErrorKind:
+        return self.args[1]
 
 
 class IOError(StringError):
@@ -54,35 +57,22 @@ class TemplateError(StringError):
     pass
 
 
-SyncErrorKind = pb.SyncError.SyncErrorKind
-
-
-class SyncError(StringError):
-    def kind(self) -> SyncErrorKind:
-        return self.args[1]
-
-    def localized(self) -> str:
-        return self.args[2]
-
-
 def proto_exception_to_native(err: pb.BackendError) -> Exception:
     val = err.WhichOneof("value")
     if val == "interrupted":
         return Interrupted()
     elif val == "network_error":
-        e = err.network_error
-        return NetworkError(e.info, e.kind, e.localized)
-    elif val == "io_error":
-        return IOError(err.io_error.info)
-    elif val == "db_error":
-        return DBError(err.db_error.info)
-    elif val == "template_parse":
-        return TemplateError(err.template_parse.info)
-    elif val == "invalid_input":
-        return StringError(err.invalid_input.info)
+        return NetworkError(err.localized, err.network_error.kind)
     elif val == "sync_error":
-        e2 = err.sync_error
-        return SyncError(e2.info, e2.kind, e2.localized)
+        return SyncError(err.localized, err.sync_error.kind)
+    elif val == "io_error":
+        return IOError(err.localized)
+    elif val == "db_error":
+        return DBError(err.localized)
+    elif val == "template_parse":
+        return TemplateError(err.localized)
+    elif val == "invalid_input":
+        return StringError(err.localized)
     else:
         assert_impossible_literal(val)
 

qt/aqt/mediasync.py

@@ -14,10 +14,8 @@ from anki.rsbackend import (
     FString,
     Interrupted,
     MediaSyncProgress,
-    NetworkError,
     Progress,
     ProgressKind,
-    SyncError,
 )
 from anki.types import assert_impossible
 from anki.utils import intTime
@@ -109,13 +107,7 @@ class MediaSyncer:
             return
 
         self._log_and_notify(tr(FString.SYNC_MEDIA_FAILED))
-        if isinstance(exc, SyncError):
-            showWarning(exc.localized())
-        elif isinstance(exc, NetworkError):
-            msg = exc.localized()
-            msg += "\n\n" + tr(FString.NETWORK_DETAILS, details=str(exc))
-        else:
-            raise exc
+        showWarning(str(exc))
 
     def entries(self) -> List[LogEntryWithTime]:
         return self._log

rslib/src/backend.rs

@@ -45,23 +45,24 @@ fn anki_error_to_proto_error(err: AnkiError, i18n: &I18n) -> pb::BackendError {
     let localized = err.localized_description(i18n);
     let value = match err {
         AnkiError::InvalidInput { info } => V::InvalidInput(pb::StringError { info }),
-        AnkiError::TemplateError { info } => V::TemplateParse(pb::TemplateParseError { info }),
+        AnkiError::TemplateError { info } => V::TemplateParse(pb::StringError { info }),
         AnkiError::IOError { info } => V::IoError(pb::StringError { info }),
         AnkiError::DBError { info } => V::DbError(pb::StringError { info }),
         AnkiError::NetworkError { info, kind } => V::NetworkError(pb::NetworkError {
             info,
             kind: kind.into(),
-            localized,
         }),
         AnkiError::SyncError { info, kind } => V::SyncError(pb::SyncError {
             info,
             kind: kind.into(),
-            localized,
         }),
         AnkiError::Interrupted => V::Interrupted(Empty {}),
     };
 
-    pb::BackendError { value: Some(value) }
+    pb::BackendError {
+        value: Some(value),
+        localized,
+    }
 }
 
 // Convert an Anki error to a protobuf output.

rslib/src/err.rs

@@ -1,7 +1,7 @@
 // Copyright: Ankitects Pty Ltd and contributors
 // License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
-use crate::i18n::{FString, I18n};
+use crate::i18n::{tr_strs, FString, I18n};
 pub use failure::{Error, Fail};
 use reqwest::StatusCode;
 use std::io;
@@ -67,13 +67,16 @@ impl AnkiError {
                 SyncErrorKind::ResyncRequired => i18n.tr(FString::SyncResyncRequired),
             }
             .into(),
-            AnkiError::NetworkError { kind, .. } => match kind {
-                NetworkErrorKind::Offline => i18n.tr(FString::NetworkOffline),
-                NetworkErrorKind::Timeout => i18n.tr(FString::NetworkTimeout),
-                NetworkErrorKind::ProxyAuth => i18n.tr(FString::NetworkProxyAuth),
-                NetworkErrorKind::Other => i18n.tr(FString::NetworkOther),
+            AnkiError::NetworkError { kind, info } => {
+                let summary = match kind {
+                    NetworkErrorKind::Offline => i18n.tr(FString::NetworkOffline),
+                    NetworkErrorKind::Timeout => i18n.tr(FString::NetworkTimeout),
+                    NetworkErrorKind::ProxyAuth => i18n.tr(FString::NetworkProxyAuth),
+                    NetworkErrorKind::Other => i18n.tr(FString::NetworkOther),
+                };
+                let details = i18n.trn(FString::NetworkDetails, tr_strs!["details"=>info]);
+                format!("{}\n{}", summary, details)
             }
-            .into(),
             _ => "".into(),
         }
     }