When `parentPort.on('message', fn)` is called, `injectFakeEmitter.on()` wraps `fn` into a `callback` (setting `fn[wrappedListener] = callback`) and registers `callback` with `parentPortAddEventListener` — so `trackedByListener` is keyed on `callback`, not `fn`. When `parentPort.removeListener('message', fn)` is called, it invokes `parentPortRemoveEventListener('message', fn)` directly; `trackedByListener.get(fn)` returns `undefined`, the call returns early, and the listener is never removed. Thi

When a worker sets only `parentPort.onmessageerror = handler` (or calls `parentPort.on('messageerror', fn)` / `parentPort.addEventListener('messageerror', fn)`) without registering any `message` listener, `acquireListener()` fires and `installForwarders()` unconditionally installs BOTH the `messageForwarder` AND `messageErrorForwarder` on `self` with `capture: true`. Installing the `message` forwarder on `self` increments `m_messageEventCount` in `BunWorkerGlobalScope.cpp` and calls `refEventLoo