GeezerVison

Supersedes #2065, which GitHub closed when its base branch (feat/worker-threads) was deleted at the #2043 squash. The four commits are @adrian-niculescu's, replayed onto main with authorship kept, plus one comment fix.

A parentPort.on("message") listener that throws never reaches the worker's onerror or the parent's worker.on("error"). The relay dispatched without rethrowing, so the throw went to the uncaught-error reporter and stopped there. It now dispatches the way worker-global message delivery does.

A worker.on("error") listener received the runtime's ErrorEvent instead of an Error, and an error it handled was also reported to the parent's global scope as unhandled. The worker now sends the thrown value's name and message with the error payload, and the parent rebuilds an Error from them and the worker's stack, with the built-in constructor when the name is a built-in one. The listener receives that Error, as in Node. The emitter's emit reports whether a listener ran, as Node's does, and the Worker cancels the event when one did. An error nothing handled reaches the parent's global error event carrying the same Error.

A once listener could fire twice: when an earlier listener emitted the same event again, the nested emit fired and removed it, and the outer emit then called it a second time from its snapshot. A once registration now records that it fired, as Node's once wrapper does, so a once listener an earlier listener removed still fires, as in Node.

The same fix for iOS is NativeScript/ios#491. Replaying onto main meant reconciling with #2044's nsworkerended callout. WorkerEvents.h declares both the new EmitError (which returns the rebuilt error, or undefined when handled) and EmitEnded. worker-events.js exports { emitMessage, emitError, emitEnded, kWorkerError }, and the Worker row in docs/worker-threads.md keeps the exit sentence and adds the rebuilt-Error one. worker-events.js and node-worker-threads.js now match iOS main apart from platform comments and iOS's ns:worker_threads require (ios#494, not ported). The extra commit carries the #reportExit comment fix from the ios#491 review, which hadn't reached the Android branch.

Merge after #2088. This branch is stacked on it and #2087, so until those squashes land the diff here also shows their commits. Full device suite with all three applied: 1467 specs, 0 failures.

Summary by CodeRabbit

• Bug Fixes

  • Message delivery now preserves undefined and other falsy values across messaging channels, and distinguishes delivered data from default event data.
  • Unreadable messages report a messageerror with a consistent null fallback when no error value is available.
  • Worker errors retain their name, message, and stack when available. Unhandled errors reach the parent scope; handled errors are suppressed there.
  • Objects marked as uncloneable are recognized during cloning, including when marked after serialization setup.
  • Worker error listeners now handle reentrant one-time registrations consistently.

• Documentation

  • Clarified how worker errors are reconstructed and delivered to listeners.