All: Fixes 12810: Ensure the sync shows an error when the server is down, when using a local WebDAV server (#13301)

packages/lib/Synchronizer.ts

@@ -20,7 +20,7 @@ import JoplinError from './JoplinError';
 import ShareService from './services/share/ShareService';
 import TaskQueue from './TaskQueue';
 import ItemUploader from './services/synchronizer/ItemUploader';
-import { FileApi, getSupportsDeltaWithItems, PaginatedList, RemoteItem } from './file-api';
+import { FileApi, getSupportsDeltaWithItems, isLocalServer, PaginatedList, RemoteItem } from './file-api';
 import JoplinDatabase from './JoplinDatabase';
 import { checkIfCanSync, fetchSyncInfo, checkSyncTargetIsValid, getActiveMasterKey, localSyncInfo, mergeSyncInfos, saveLocalSyncInfo, setMasterKeyHasBeenUsed, SyncInfo, syncInfoEquals, uploadSyncInfo } from './services/synchronizer/syncInfoUtils';
 import { getMasterPassword, setupAndDisableEncryption, setupAndEnableEncryption } from './services/e2ee/utils';
@@ -32,6 +32,7 @@ import syncDeleteStep from './services/synchronizer/utils/syncDeleteStep';
 import { ErrorCode } from './errors';
 import { SyncAction } from './services/synchronizer/utils/types';
 import checkDisabledSyncItemsNotification from './services/synchronizer/utils/checkDisabledSyncItemsNotification';
+import SyncTargetRegistry from './SyncTargetRegistry';
 const { sprintf } = require('sprintf-js');
 const { Dirnames } = require('./services/synchronizer/utils/types');
 
@@ -1164,8 +1165,13 @@ export default class Synchronizer {
 				logger.error(error);
 				if (error.details) logger.error('Details:', error.details);
 
-				// Don't save to the report errors that are due to things like temporary network errors or timeout.
+				const isLocalWebDavServer = Setting.value('sync.target') === SyncTargetRegistry.nameToId('webdav') && isLocalServer(Setting.value('sync.6.path'));
-				if (!shim.fetchRequestCanBeRetried(error)) {
+
+				// Don't save to the report errors that are due to things like temporary network errors or timeout, except if using a local WebDAV server, in which
+				// case timeout errors can occur when the server is actually down. Those type of errors happen consistently when a local server is down when using
+				// the Android app in particular, but they can also happen on the desktop app in some circumstances. The usage of a local WebDAV server is most useful
+				// on Android, as it can be used as an alternative to file system sync, in order to work around performance issues related to SAF
+				if (!shim.fetchRequestCanBeRetried(error) || isLocalWebDavServer) {
 					this.progressReport_.errors.push(error);
 					this.logLastRequests();
 				}

packages/lib/file-api.test.ts

@@ -1,4 +1,4 @@
-import { PaginatedList, RemoteItem, getSupportsDeltaWithItems } from './file-api';
+import { PaginatedList, RemoteItem, getSupportsDeltaWithItems, isLocalServer } from './file-api';
 
 const defaultPaginatedList = (): PaginatedList => {
 	return {
@@ -70,4 +70,28 @@ describe('file-api', () => {
 		expect(actual).toBe(expected);
 	});
 
+	it.each([
+		'http://localhost',
+		'http://localhost/',
+		'https://localhost:8080',
+		'http://127.0.0.1',
+		'https://127.100.50.25:3000/test',
+		'http://[::1]',
+		'http://localhost/api/v1',
+	])('should detect a local server url', (url: string) => {
+		const result = isLocalServer(url);
+		expect(result).toBe(true);
+	});
+
+	it.each([
+		'http://localhostXYZ',
+		'http://127.0.0.1foobar',
+		'http://192.168.1.1',
+		'http://example.com',
+		'https://my-localhost.com',
+	])('should detect a non local server url', (url: string) => {
+		const result = isLocalServer(url);
+		expect(result).toBe(false);
+	});
+
 });

packages/lib/file-api.ts

@@ -53,6 +53,11 @@ export const getSupportsDeltaWithItems = (deltaResponse: PaginatedList) => {
 	return 'jopItem' in deltaResponse.items[0];
 };
 
+export const isLocalServer = (url: string) => {
+	const regex = /^(https?:\/\/)?(localhost|127(?:\.\d{1,3}){3}|\[::1\])(?::\d{1,5})?(\/.*)?$/i;
+	return regex.test(url);
+};
+
 // eslint-disable-next-line @typescript-eslint/no-explicit-any -- Old code before rule was applied
 function requestCanBeRepeated(error: any) {
 	const errorCode = typeof error === 'object' && error.code ? error.code : null;