the "enteredExecutionContext" method doesn't return the correct context during microtask execution.

The code assumes that it's safe to fallback to the current context, however, we might have an entered context, e.g., when some js code dispatches an event, and at the end of the event dispatch we'll execute microtasks. Then the js code is still the entered execution context, so we'll get a non-null context, which is, however, entirely unrelated to the service worker.

I'd argue that microtasks should enter a context, it's however not trivially clear what context that should be - the context of the Promise constructor? The creation context of the microtask function?

Putting the security label on this, because I could imagine that a more creative person can turn this into some code that takes over a service worker cross domain