eventEmitter.removeListener calls removed listener within emit cycle

[RGBboy]

I am trying to remove an event listener during the emit cycle of an event. I would have thought the following code would not fail. Am I right in this assumption or should all of these event listeners be called?

  var emitter = new EventEmitter();

  t.plan(2);

  function one () {
    t.ok('called');
    emitter.removeListener('test', two);
  };

  function two () {
    t.fail('should not be called');
  };

  function three () {
    t.ok('called');
  };

  emitter.on('test', one);
  emitter.on('test', two);
  emitter.on('test', three);

  emitter.emit('test');

[jfhbrook]

Two should fire exactly once.

[jfhbrook]

If this was buggy, it would fire twice.

[RGBboy]

OK thanks. Is there a way to prevent listeners from being called if they are removed during the emit cycle?

[jfhbrook]

Don't create them during the emit cycle. ;) Do it on the next tick or similar.

[indutny]

This is an intended behavior, sorry. Please continue the discussion on a mailing list.

[kenzanboo]

@indutny
The node documentation for emit says that emit will "Execute each of the listeners in order ... " so if the first listener removes the second listener, it would be expected that the second listener does not get executed. In the above example, because listener one removes the listener two, and it is executed first, two should not have executed.
None of the removeListener code is deferred so it should update this._event immediately.

[lxe]

The event API (whose interface is frozen) doc specify:

emitter.emit(event, [arg1], [arg2], [...])
Execute each of the listeners in order with the supplied arguments.

The emitters must be executed in order with which they were attached.

Furthermore, there is nothing in lib/events.js that defers the execution of removeListener.
I think this still should be addressed, or at the least, the docs need to be changed to reflect this behavior.