napi backend: class-cluster return values lose their concrete API surface — NSURLSessionWebSocketTask arrives bridged as NSURLSessionTask

Ouverte
  • Quelque chose ne va pas ?
#110 0 commentaires 0 réactions 0 personnes assignées Voir sur GitHub

Les mainteneurs répondent en général sous 1 jour

Personne n'a encore pris cette issue.

Évaluation

Difficulté
5/5
Temps estimé
Plus d'une semaine
Accessibilité débutants
22/100
Type d'issue
Bug
Clarté
Plutôt claire
Activité
Active
Stack technique
cpp, objective-c
Domaine
desktop-dev

Piste de recherche

The problem is in how the napi backend picks a JS wrapper for a returned Objective-C object: the isa-chain walk stops at the first metadata-registered class, which lands above the declared return type. Start from that resolution step and reproduce with NSURLSession.sharedSession.webSocketTaskWithURL, checking whether sendMessageCompletionHandler is present on the returned wrapper. Done means the wrapper exposes the NSURLSessionWebSocketTask members without the setPrototypeOf workaround; the fix design needs maintainer input first.

Rédigé par le modèle d'indexation à partir du texte de l'issue.

Description

Summary

When a bridged API returns a private class-cluster subclass, the JS wrapper is resolved by walking the real isa chain to the first metadata-registered class — so it lands below the declared return type and the concrete API surface is unreachable from JS.

NSURLSession.sharedSession.webSocketTaskWithURL(...) returns __NSURLSessionWebSocketTask (isa chain: __NSURLSessionWebSocketTask → __NSCFLocalSessionTask → NSURLSessionTask → NSObject). NSURLSessionWebSocketTask is metadata-registered and fully bridged — its prototype has every member — and task.isKindOfClass(NSURLSessionWebSocketTask) is true, but the returned wrapper exposes only NSURLSessionTask members: sendMessageCompletionHandler and receiveMessageWithCompletionHandler are undefined, so calls throw TypeError. Private cluster classes can't enter public-header metadata, so the ws level is never reached by the isa walk.

Expected

When isa-walk resolution lands on an ancestor of the metadata-declared return type, the wrapper could be built from the declared type; alternatively, an opt-in way to repoint a wrapper to a registered subclass the object isKindOfClass:es would cover the same ground.

Workaround we run today: Object.setPrototypeOf(task, NSURLSessionWebSocketTask.prototype) when the ws members are missing — every member then dispatches correctly, including closeCode/closeReason. A minimal regression check for a fix is that the returned task exposes sendMessageCompletionHandler without the repoint.

Environment

  • NativeScript/runtimes 5b697b39, generic napi backend, TARGET_PLATFORM=macos, arm64
  • NSURLSessionWebSocketTask requires macOS 10.15+; runtime-verified — this is wrapper resolution, not a metadata absence.
Langage dominant
C++
Étoiles
27
Forks
4
Merge moyen
5 j 11 h
PR mergées (30 j)
12

Préparer son environnement

Par où commencer

  1. Lisez l'issue en entier, puis le guide de contribution du projet.
  2. Signalez en commentaire que vous la prenez — cela évite que deux personnes fassent le même travail.
  3. Forkez le dépôt et travaillez sur une branche.
  4. Ouvrez une pull request qui référence le numéro de l'issue.

Autres issues de NativeScript/runtimes

Toutes les issues de NativeScript/runtimes

Issues similaires

Plus d'issues C++

Recevez les nouvelles issues par e-mail

Un résumé court des issues GitHub adaptées aux débutants.