fix(sync): Recover stalled model synchronization by nfebe · Pull Request #219 · trakli/mobile

nfebe · 2026-08-15T00:37:09Z

Fixes reports of transactions, parties, and transfers remaining local or never appearing in Last Sync Status. Local writes now commit with their pending change without waiting for the network, orphan recovery covers every locally writable sync model, and each model shows its latest attempt or failure.

Local writes and their pending changes now commit together without making saves wait for the network. Missing local changes are recovered across synchronized models, transfer downloads continue safely after transaction failures, and per-model attempts remain visible even when no records are returned.

sourceant · 2026-08-15T00:38:31Z

Code Review Summary

This PR implements a robust orphan recovery mechanism and standardizes persistence patterns across the repository layer. It also enhances sync status visibility in the UI and improves network stability through HTTP timeouts.

🚀 Key Improvements

Implemented comprehensive orphan recovery for all locally writable models in SynchAppDatabase.
Added Dio timeouts to mitigate issues with stalled network connections in http_module.dart.
Enhanced Sync History UI with detailed error reporting and status tracking.
Refactored repositories to use centralized persistAnd... methods for improved consistency.

💡 Minor Suggestions

Ensure that all new synced entities (like category and media_file) are fully localized in the UI switch statements.
Consider replacing null-assertion operators with safe checks in repository update methods.

🚨 Critical Issues

Several repository deletion methods lack null checks for entities fetched by client ID, which poses a significant crash risk if a record is missing at the time of deletion.

sourceant

Review complete. See the overview comment for a summary.

sourceant · 2026-08-15T00:38:32Z

+        ..sort((a, b) => a.entityType.compareTo(b.entityType));
      final allChanges = await _db.select(_db.localChanges).get();

      // Quarantined changes are permanently failed and never retry


The entity type 'media_file' (defined in MediaSyncHandler.entity) is missing from the switch statement. Users will see the raw entity key instead of a localized string in the Sync History UI.

Suggested change

// Quarantined changes are permanently failed and never retry

case 'party':

return LocaleKeys.party.tr();

case 'group':

return LocaleKeys.group.tr();

case 'media_file':

return LocaleKeys.media.tr();

case 'transfer':

return LocaleKeys.transfer.tr();

sourceant · 2026-08-15T00:38:32Z

+              .map((t) => BudgetTargetInput(type: t.type, clientId: t.clientId))
+              .toList(),
+        );
+        return (await _composeDto(budget.clientId))!;


The null-assertion operator ! is used here. While composition is expected to succeed immediately after an insert, it is safer to handle a potential null DTO or use a more defensive approach to prevent runtime crashes if database constraints or relations are unexpectedly missing.

Suggested change

return (await _composeDto(budget.clientId))!;

final dto = await _composeDto(budget.clientId);

if (dto == null) throw Exception('Failed to compose Budget DTO');

return dto;

nfebe · 2026-08-15T00:55:59Z

    git:
      url: https://github.com/whilesmartflutter/drift_sync.git
-      ref: drift_sync_core-v0.3.3
+      ref: 4ac6cf0


@austin047 Once whilesmartflutter/drift_sync#2 is merged, you can retag?

Every repository awaited `delete`, which awaits the remote call, so deleting a record held the UI for a full network round trip. The cubits already remove the row optimistically, but `isDeleting` stayed true until the request settled. Switch to `persistAndDelete`, which returns once the deletion and its outbox entry are durable and leaves delivery to the sync loop - the same shape create and update already use. The Dio instance set no timeouts, so a stalled connection fell through to the OS socket timeout and could hang a request for minutes. Bound connect, send and receive. Also rename the transfer handler override to match `downloadIgnoresFailedDependencies`.

A down-sync failure was rendered as a bare red icon that replaced the timestamp, so the screen said a model was broken without saying why or when it last tried - and unlike upload failures there is no queued change to inspect, so the error was unreachable from the UI entirely. Keep the last-attempted timestamp visible next to the icon, show a one-line excerpt of the error inline, and make the row open a dialog with the full selectable text. Regenerating the localization keys also picked up five export* keys that were already in the JSON but missing from locale_keys.g.dart.

sourceant

Review complete. No specific code suggestions were generated. See the overview comment for a summary.

…Delete The ref was still 4ac6cf0, which predates `persistAndDelete` and the `downloadIgnoresFailedDependencies` rename, so CI could not compile the repositories. Still a bare SHA, as before - it moves to drift_sync_core-v0.3.4 once that release is cut.

sourceant

Review complete. See the overview comment for a summary.

sourceant · 2026-08-16T11:59:33Z

+      );
      for (final clientId in orphanIds) {
        try {
          final entity = await handler.getLocalByClientId(clientId);


The result of getLocalByClientId should be null-checked. If an entity was deleted or changed between the time orphanIds were identified and this iteration, the handler might return null, leading to a crash in the subsequent sync engine logic.

Suggested change

final entity = await handler.getLocalByClientId(clientId);

final entity = await handler.getLocalByClientId(clientId);

if (entity == null) continue;

sourceant · 2026-08-16T11:59:33Z

    return RepositoryErrorHandler.handleApiCall(() async {
-      final category = await localDataSource.deleteCategory(clientId);
-      unawaited(delete(category));
+      final category = await syncHandler.getLocalByClientId(clientId);


The syncHandler.getLocalByClientId call can return null if the category does not exist or was already removed. Passing null to persistAndDelete will cause a runtime exception. It is better to verify the entity exists and return a descriptive failure if it is missing.

Suggested change

final category = await syncHandler.getLocalByClientId(clientId);

final category = await syncHandler.getLocalByClientId(clientId);

if (category == null) return Left(Failure.cacheError('Category not found'));

await persistAndDelete(category);

sourceant · 2026-08-16T11:59:33Z

  Future<Either<Failure, Unit>> deleteTransaction(String id) async {
    try {
-      final transaction = await localDataSource.deleteTransaction(id);
+      final transaction = await syncHandler.getLocalByClientId(id);


Adding a null check for the transaction before deletion prevents runtime crashes in case of invalid or missing IDs. This ensures the repository returns a clean failure rather than an unhandled exception.

Suggested change

final transaction = await syncHandler.getLocalByClientId(id);

final transaction = await syncHandler.getLocalByClientId(id);

if (transaction == null) return Left(Failure.cacheError('Transaction not found'));

await persistAndDelete(transaction);

sourceant Bot suggested changes Aug 15, 2026

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nfebe commented Aug 15, 2026

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nfebe requested a review from austin047 August 15, 2026 09:57

austin047 added 2 commits August 16, 2026 00:48

sourceant Bot approved these changes Aug 16, 2026

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austin047 and others added 2 commits August 16, 2026 04:01

build(deps): Use drift_sync_core 0.3.4 release

20743b9

sourceant Bot suggested changes Aug 16, 2026

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austin047 approved these changes Aug 16, 2026

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austin047 merged commit e96ea4c into dev Aug 16, 2026
3 checks passed

austin047 deleted the fix/sync-queue-recovery branch August 16, 2026 19:27

austin047 mentioned this pull request Aug 16, 2026

chore(release): Bump version to 2.0.1 #220

Merged

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fix(sync): Recover stalled model synchronization - #219

fix(sync): Recover stalled model synchronization#219
austin047 merged 5 commits into
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fix/sync-queue-recovery

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-      // Quarantined changes are permanently failed and never retry
+      case 'party':
+        return LocaleKeys.party.tr();
+      case 'group':
+        return LocaleKeys.group.tr();
+      case 'media_file':
+        return LocaleKeys.media.tr();
+      case 'transfer':
+        return LocaleKeys.transfer.tr();

-        return (await _composeDto(budget.clientId))!;
+        final dto = await _composeDto(budget.clientId);
+        if (dto == null) throw Exception('Failed to compose Budget DTO');
+        return dto;

	final entity = await handler.getLocalByClientId(clientId);
	final entity = await handler.getLocalByClientId(clientId);
	if (entity == null) continue;

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Code Review Summary

🚀 Key Improvements

💡 Minor Suggestions

🚨 Critical Issues

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sourceant Bot commented Aug 15, 2026 •

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